U.S. patent application number 17/341421 was filed with the patent office on 2021-12-30 for method and apparatus for user equipment (ue) reporting sidelink ue capability information in a wireless communication system.
The applicant listed for this patent is ASUSTek Computer Inc.. Invention is credited to Richard Lee-Chee Kuo.
Application Number | 20210409937 17/341421 |
Document ID | / |
Family ID | 1000005680018 |
Filed Date | 2021-12-30 |
United States Patent
Application |
20210409937 |
Kind Code |
A1 |
Kuo; Richard Lee-Chee |
December 30, 2021 |
METHOD AND APPARATUS FOR USER EQUIPMENT (UE) REPORTING SIDELINK UE
CAPABILITY INFORMATION IN A WIRELESS COMMUNICATION SYSTEM
Abstract
A method and device are disclosed from the perspective of a
second User Equipment (UE) to report sidelink capability
information. In one embodiment, the method includes the second UE
receiving, from a UE-to-UE Relay, a first sidelink UE capability
information of a first UE and a second sidelink UE capability
information of the UE-to-UE Relay or receives, from the UE-to-UE
Relay, a combined sidelink UE capability information, wherein the
combined sidelink UE capability information is derived from the
first sidelink UE capability information and the second sidelink UE
capability information. The method further includes the second UE
transmits the first sidelink UE capability information and the
second sidelink UE capability information to a network node or
transmits the combined sidelink UE capability information to the
network node.
Inventors: |
Kuo; Richard Lee-Chee;
(Taipei City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ASUSTek Computer Inc. |
Taipei City 112 |
|
TW |
|
|
Family ID: |
1000005680018 |
Appl. No.: |
17/341421 |
Filed: |
June 8, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
63045726 |
Jun 29, 2020 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 28/0268 20130101;
H04W 8/24 20130101; H04W 88/04 20130101; H04W 28/0252 20130101 |
International
Class: |
H04W 8/24 20060101
H04W008/24; H04W 28/02 20060101 H04W028/02; H04W 88/04 20060101
H04W088/04 |
Claims
1. A method for a second User Equipment (UE) to report sidelink
capability information, comprising: the second UE receives, from a
UE-to-UE Relay, a first sidelink UE capability information of a
first UE and a second sidelink UE capability information of the
UE-to-UE Relay or receives, from the UE-to-UE Relay, a combined
sidelink UE capability information, wherein the combined sidelink
UE capability information is derived from the first sidelink UE
capability information and the second sidelink UE capability
information; and the second UE transmits the first sidelink UE
capability information and the second sidelink UE capability
information to a network node or transmits the combined sidelink UE
capability information to the network node.
2. The method of claim 1, wherein the first UE communicates with
the second UE via the UE-to-UE Relay.
3. The method of claim 1, wherein the first sidelink UE capability
information and the second sidelink UE capability information are
received via one first PC5 Radio Resource Control (RRC) message,
two first PC5 RRC messages, or a first PC5 RRC message and a second
PC5 RRC message.
4. The method of claim 1, wherein the combined sidelink UE
capability information is transmitted to the network node via a
Sidelink UE Information message.
5. The method of claim 1, wherein the first sidelink UE capability
information and the second sidelink UE capability information are
transmitted to the network node via a Sidelink UE Information
message.
6. The method of claim 5, wherein the Sidelink UE Information
message includes a destination identity of the UE-to-UE Relay, a
cast type of the sidelink communication, and/or Quality of Service
(QoS) information of a PC5 QoS flow.
7. The method of claim 6, wherein the cast type is set to
"unicast".
8. The method of claim 6, wherein the QoS information includes a
QoS flow identity and a QoS profile.
9. The method of claim 1, further comprising: the second UE
transmits a third sidelink UE capability information of the second
UE to the network node, wherein the third sidelink UE capability
information is transmitted in a UE Capability Information
message.
10. The method of claim 1, further comprising: the second UE
receives a Radio Resource Control (RRC) Reconfiguration message
from the network node to allocate a sidelink configuration for the
sidelink communication, wherein the sidelink configuration includes
a configuration of a sidelink Data Radio Bearer (DRB) mapped to a
PC5 Quality of Service (QoS) flow.
11. A second User Equipment (UE), comprising: a control circuit; a
processor installed in the control circuit; and a memory installed
in the control circuit and operatively coupled to the processor;
wherein the processor is configured to execute a program code
stored in the memory to: receive, from a UE-to-UE Relay, a first
sidelink UE capability information of a first UE and a second
sidelink UE capability information of the UE-to-UE Relay or
receives, from the UE-to-UE Relay, a combined sidelink UE
capability information, wherein the combined sidelink UE capability
information is derived from the first sidelink UE capability
information and the second sidelink UE capability information; and
transmit the first sidelink UE capability information and the
second sidelink UE capability information to a network node or
transmits the combined sidelink UE capability information to the
network node.
12. The second UE of claim 11, wherein the first UE communicates
with the second UE via the UE-to-UE Relay.
13. The second UE of claim 11, wherein the first sidelink UE
capability information and the second sidelink UE capability
information are received via one first PC5 Radio Resource Control
(RRC) message, two first PC5 RRC messages, or a first PC5 RRC
message and a second PC5 RRC message.
14. The second UE of claim 11, wherein the combined sidelink UE
capability information is transmitted to the network node via a
Sidelink UE Information message.
15. The second UE of claim 11, wherein the first sidelink UE
capability information and the second sidelink UE capability
information are transmitted to the network node via a Sidelink UE
Information message.
16. The second UE of claim 11, wherein the Sidelink UE Information
message includes a destination identity of the UE-to-UE Relay, a
cast type of the sidelink communication, and/or Quality of Service
(QoS) information of a PC5 QoS flow.
17. The second UE of claim 16, wherein the cast type is set to
"unicast".
18. The second UE of claim 16, wherein the QoS information includes
a QoS flow identity and a QoS profile.
19. The second UE of claim 11, wherein the processor is further
configured to execute the program code stored in the memory to:
transmit a third sidelink UE capability information of the second
UE to the network node, wherein the third sidelink UE capability
information is transmitted in a UE Capability Information
message.
20. The second UE of claim 11, wherein the processor is further
configured to execute the program code stored in the memory to:
receive a Radio Resource Control (RRC) Reconfiguration message from
the network node to allocate a sidelink configuration for the
sidelink communication, wherein the sidelink configuration includes
a configuration of a sidelink Data Radio Bearer (DRB) mapped to a
PC5 Quality of Service (QoS) flow.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S.
Provisional Patent Application Ser. No. 63/045,726 filed on Jun.
29, 2020, the entire disclosure of which is incorporated herein in
its entirety by reference.
FIELD
[0002] This disclosure generally relates to wireless communication
networks, and more particularly, to a method and apparatus for User
Equipment (UE) reporting sidelink UE capability information in a
wireless communication system.
BACKGROUND
[0003] With the rapid rise in demand for communication of large
amounts of data to and from mobile communication devices,
traditional mobile voice communication networks are evolving into
networks that communicate with Internet Protocol (IP) data packets.
Such IP data packet communication can provide users of mobile
communication devices with voice over IP, multimedia, multicast and
on-demand communication services.
[0004] An exemplary network structure is an Evolved Universal
Terrestrial Radio Access Network (E-UTRAN). The E-UTRAN system can
provide high data throughput in order to realize the above-noted
voice over IP and multimedia services. A new radio technology for
the next generation (e.g., 5G) is currently being discussed by the
3GPP standards organization. Accordingly, changes to the current
body of 3GPP standard are currently being submitted and considered
to evolve and finalize the 3GPP standard.
SUMMARY
[0005] A method and device are disclosed from the perspective of a
second User Equipment (UE) to report sidelink capability
information. In one embodiment, the method includes the second UE
receiving, from a UE-to-UE Relay, a first sidelink UE capability
information of a first UE and a second sidelink UE capability
information of the UE-to-UE Relay or receives, from the UE-to-UE
Relay, a combined sidelink UE capability information, wherein the
combined sidelink UE capability information is derived from the
first sidelink UE capability information and the second sidelink UE
capability information. The method further includes the second UE
transmits the first sidelink UE capability information and the
second sidelink UE capability information to a network node or
transmits the combined sidelink UE capability information to the
network node.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 shows a diagram of a wireless communication system
according to one exemplary embodiment.
[0007] FIG. 2 is a block diagram of a transmitter system (also
known as access network) and a receiver system (also known as user
equipment or UE) according to one exemplary embodiment.
[0008] FIG. 3 is a functional block diagram of a communication
system according to one exemplary embodiment.
[0009] FIG. 4 is a functional block diagram of the program code of
FIG. 3 according to one exemplary embodiment.
[0010] FIG. 5 is a reproduction of FIG. 5.2.1.4-1 of 3GPP TS 23.287
V16.2.0.
[0011] FIG. 6 is a reproduction of FIG. 6.1.1-1 of 3GPP TS 23.287
V16.2.0.
[0012] FIG. 7 is a reproduction of FIG. 6.1.2-1 of 3GPP TS 23.287
V16.2.0.
[0013] FIG. 8 is a reproduction of FIG. 6.3.3.1-1 of 3GPP TS 23.287
V16.2.0.
[0014] FIG. 9 is a reproduction of FIG. 6.1.2.2.2 of 3GPP TS 24.587
V16.0.0.
[0015] FIG. 10 is a reproduction of FIG. 5.6.1.1-1 of 3GPP TS
38.331 V16.0.0.
[0016] FIG. 11 is a reproduction of FIG. 5.8.3.1-1 of 3GPP TS
38.331 V16.0.0.
[0017] FIG. 12 is a reproduction of FIG. 5.8.3.1-1 of 3GPP
R2-2005973.
[0018] FIG. 13 is a reproduction of FIG. 5.8.9.2.1-1 of 3GPP
R2-2005973.
[0019] FIG. 14 is a reproduction of FIG. 6.8.2-1 of 3GPP TR 23.752
V0.3.0.
[0020] FIG. 15 is a reproduction of FIG. 6.9.2-1 of 3GPP TR 23.752
V0.3.0.
[0021] FIG. 16 is a reproduction of FIG. 6.10.2-1 of 3GPP TR 23.752
V0.3.0.
[0022] FIG. 17 illustrates an exemplary integrated PC5 unicast link
via a UE-to-UE Relay according to one embodiment.
[0023] FIG. 18 illustrates an exemplary integrated sidelink UE
capability transfer procedure according to one embodiment.
[0024] FIG. 19 is a flow chart according to one exemplary
embodiment.
DETAILED DESCRIPTION
[0025] The exemplary wireless communication systems and devices
described below employ a wireless communication system, supporting
a broadcast service. Wireless communication systems are widely
deployed to provide various types of communication such as voice,
data, and so on. These systems may be based on code division
multiple access (CDMA), time division multiple access (TDMA),
orthogonal frequency division multiple access (OFDMA), 3GPP LTE
(Long Term Evolution) wireless access, 3GPP LTE-A or LTE-Advanced
(Long Term Evolution Advanced), 3GPP2 UMB (Ultra Mobile Broadband),
WiMax, 3GPP NR (New Radio), or some other modulation
techniques.
[0026] In particular, the exemplary wireless communication systems
and devices described below may be designed to support one or more
standards such as the standard offered by a consortium named "3rd
Generation Partnership Project" referred to herein as 3GPP,
including: TS 23.287 V16.2.0, "Architecture enhancements for 5G
System (5GS) to support Vehicle-to-Everything (V2X) services
(Release 16)"; TS 24.587 V16.0.0, "Vehicle-to-Everything (V2X)
services in 5G System (5GS); Stage 3 (Release 16)"; TS 38.331
V16.0.0, "NR; Radio Resource Control (RRC) protocol specification
(Release 16)"; R2-2005973, "Draft-CR for V2X UE capability
(focusing on RAN2 capability)"; TR 23.752 V0.3.0, "Study on system
enhancement for Proximity based services (ProSe) in the 5G System
(5GS) (Release 17)". The standards and documents listed above are
hereby expressly incorporated by reference in their entirety.
[0027] FIG. 1 shows a multiple access wireless communication system
according to one embodiment of the invention. An access network 100
(AN) includes multiple antenna groups, one including 104 and 106,
another including 108 and 110, and an additional including 112 and
114. In FIG. 1, only two antennas are shown for each antenna group,
however, more or fewer antennas may be utilized for each antenna
group. Access terminal 116 (AT) is in communication with antennas
112 and 114, where antennas 112 and 114 transmit information to
access terminal 116 over forward link 120 and receive information
from access terminal 116 over reverse link 118. Access terminal
(AT) 122 is in communication with antennas 106 and 108, where
antennas 106 and 108 transmit information to access terminal (AT)
122 over forward link 126 and receive information from access
terminal (AT) 122 over reverse link 124. In a FDD system,
communication links 118, 120, 124 and 126 may use different
frequency for communication. For example, forward link 120 may use
a different frequency then that used by reverse link 118.
[0028] Each group of antennas and/or the area in which they are
designed to communicate is often referred to as a sector of the
access network. In the embodiment, antenna groups each are designed
to communicate to access terminals in a sector of the areas covered
by access network 100.
[0029] In communication over forward links 120 and 126, the
transmitting antennas of access network 100 may utilize beamforming
in order to improve the signal-to-noise ratio of forward links for
the different access terminals 116 and 122. Also, an access network
using beamforming to transmit to access terminals scattered
randomly through its coverage causes less interference to access
terminals in neighboring cells than an access network transmitting
through a single antenna to all its access terminals.
[0030] An access network (AN) may be a fixed station or base
station used for communicating with the terminals and may also be
referred to as an access point, a Node B, a base station, an
enhanced base station, an evolved Node B (eNB), a network node, a
network, or some other terminology. An access terminal (AT) may
also be called user equipment (UE), a wireless communication
device, terminal, access terminal or some other terminology.
[0031] FIG. 2 is a simplified block diagram of an embodiment of a
transmitter system 210 (also known as the access network) and a
receiver system 250 (also known as access terminal (AT) or user
equipment (UE)) in a MIMO system 200. At the transmitter system
210, traffic data for a number of data streams is provided from a
data source 212 to a transmit (TX) data processor 214.
[0032] In one embodiment, each data stream is transmitted over a
respective transmit antenna. TX data processor 214 formats, codes,
and interleaves the traffic data for each data stream based on a
particular coding scheme selected for that data stream to provide
coded data.
[0033] The coded data for each data stream may be multiplexed with
pilot data using OFDM techniques. The pilot data is typically a
known data pattern that is processed in a known manner and may be
used at the receiver system to estimate the channel response. The
multiplexed pilot and coded data for each data stream is then
modulated (i.e., symbol mapped) based on a particular modulation
scheme (e.g., BPSK, QPSK, M-PSK, or M-QAM) selected for that data
stream to provide modulation symbols. The data rate, coding, and
modulation for each data stream may be determined by instructions
performed by processor 230.
[0034] The modulation symbols for all data streams are then
provided to a TX MIMO processor 220, which may further process the
modulation symbols (e.g., for OFDM). TX MIMO processor 220 then
provides N.sub.T modulation symbol streams to N.sub.T transmitters
(TMTR) 222a through 222t. In certain embodiments, TX MIMO processor
220 applies beamforming weights to the symbols of the data streams
and to the antenna from which the symbol is being transmitted.
[0035] Each transmitter 222 receives and processes a respective
symbol stream to provide one or more analog signals, and further
conditions (e.g., amplifies, filters, and upconverts) the analog
signals to provide a modulated signal suitable for transmission
over the MIMO channel. N.sub.T modulated signals from transmitters
222a through 222t are then transmitted from N.sub.T antennas 224a
through 224t, respectively.
[0036] At receiver system 250, the transmitted modulated signals
are received by N.sub.R antennas 252a through 252r and the received
signal from each antenna 252 is provided to a respective receiver
(RCVR) 254a through 254r. Each receiver 254 conditions (e.g.,
filters, amplifies, and downconverts) a respective received signal,
digitizes the conditioned signal to provide samples, and further
processes the samples to provide a corresponding "received" symbol
stream.
[0037] An RX data processor 260 then receives and processes the
N.sub.R received symbol streams from N.sub.R receivers 254 based on
a particular receiver processing technique to provide N.sub.T
"detected" symbol streams. The RX data processor 260 then
demodulates, deinterleaves, and decodes each detected symbol stream
to recover the traffic data for the data stream. The processing by
RX data processor 260 is complementary to that performed by TX MIMO
processor 220 and TX data processor 214 at transmitter system
210.
[0038] A processor 270 periodically determines which pre-coding
matrix to use (discussed below). Processor 270 formulates a reverse
link message comprising a matrix index portion and a rank value
portion.
[0039] The reverse link message may comprise various types of
information regarding the communication link and/or the received
data stream. The reverse link message is then processed by a TX
data processor 238, which also receives traffic data for a number
of data streams from a data source 236, modulated by a modulator
280, conditioned by transmitters 254a through 254r, and transmitted
back to transmitter system 210.
[0040] At transmitter system 210, the modulated signals from
receiver system 250 are received by antennas 224, conditioned by
receivers 222, demodulated by a demodulator 240, and processed by a
RX data processor 242 to extract the reserve link message
transmitted by the receiver system 250. Processor 230 then
determines which pre-coding matrix to use for determining the
beamforming weights then processes the extracted message.
[0041] Turning to FIG. 3, this figure shows an alternative
simplified functional block diagram of a communication device
according to one embodiment of the invention. As shown in FIG. 3,
the communication device 300 in a wireless communication system can
be utilized for realizing the UEs (or ATs) 116 and 122 in FIG. 1 or
the base station (or AN) 100 in FIG. 1, and the wireless
communications system is preferably the NR system. The
communication device 300 may include an input device 302, an output
device 304, a control circuit 306, a central processing unit (CPU)
308, a memory 310, a program code 312, and a transceiver 314. The
control circuit 306 executes the program code 312 in the memory 310
through the CPU 308, thereby controlling an operation of the
communications device 300. The communications device 300 can
receive signals input by a user through the input device 302, such
as a keyboard or keypad, and can output images and sounds through
the output device 304, such as a monitor or speakers. The
transceiver 314 is used to receive and transmit wireless signals,
delivering received signals to the control circuit 306, and
outputting signals generated by the control circuit 306 wirelessly.
The communication device 300 in a wireless communication system can
also be utilized for realizing the AN 100 in FIG. 1.
[0042] FIG. 4 is a simplified block diagram of the program code 312
shown in FIG. 3 in accordance with one embodiment of the invention.
In this embodiment, the program code 312 includes an application
layer 400, a Layer 3 portion 402, and a Layer 2 portion 404, and is
coupled to a Layer 1 portion 406. The Layer 3 portion 402 generally
performs radio resource control. The Layer 2 portion 404 generally
performs link control. The Layer 1 portion 406 generally performs
physical connections.
[0043] 3GPP TS 23.287 specifies procedures related to unicast mode
V2X communication over PC5 reference point as follows:
5.1.2 Authorization and Provisioning for V2X Communications Over
PC5 Reference Point
5.1.2.1 Policy/Parameter Provisioning
[0044] The following sets of information for V2X communications
over PC5 reference point is provisioned to the UE: [0045] 1)
Authorization policy: [0046] When the UE is "served by E-UTRA" or
"served by NR": [0047] PLMNs in which the UE is authorized to
perform V2X communications over PC5 reference point when "served by
E-UTRA" or "served by NR". [0048] For each above PLMN: [0049]
RAT(s) over which the UE is authorized to perform V2X
communications over PC5 reference point. [0050] When the UE is "not
served by E-UTRA" and "not served by NR": [0051] Indicates whether
the UE is authorized to perform V2X communications over PC5
reference point when "not served by E-UTRA" and "not served by NR".
[0052] RAT(s) over which the UE is authorized to perform V2X
communications over PC5 reference point. [0053] NOTE 1: In this
specification, (When the UE is "served by E-UTRA" or "served by
NR"} and {When the UE is "not served by E-UTRA" and "not served by
NR"} are relevant to V2X communications over PC5 reference point.
[0054] 2) Radio parameters when the UE is "not served by E-UTRA"
and "not served by NR": [0055] Includes the radio parameters per
PC5 RAT (i.e. LTE PC5, NR PC5) with Geographical Area(s) and an
indication of whether they are "operator managed" or "non-operator
managed". These radio parameters (e.g., frequency bands) are
defined in TS 36.331 [14] and TS 38.331 [15]. The UE uses the radio
parameters to perform V2X communications over PC5 reference point
when "not served by E-UTRA" and "not served by NR" only if the UE
can reliably locate itself in the corresponding Geographical Area.
Otherwise, the UE is not authorized to transmit. [0056] NOTE 2:
Whether a frequency band is "operator managed" or "non-operator
managed" in a given Geographical Area is defined by local
regulations. [0057] 3) Policy/parameters per RAT for PC5 Tx Profile
selection: [0058] The mapping of V2X service types (e.g. PSIDs or
ITS-AIDS) to Tx Profiles (see TS 36.300 [9] and TS 38.300 [11] for
further information). [0059] 4) Policy/parameters related to
privacy: [0060] The list of V2X service types, e.g. PSIDs or
ITS-AIDS of the V2X applications, with Geographical Area(s) that
require privacy support. [0061] A privacy timer value indicating
the duration after which the UE shall change each source Layer-2 ID
self-assigned by the UE when privacy is required. [0062] 5)
Policy/parameters when LTE PC5 is selected: [0063] Same as
specified in TS 23.285 [8] clause 4.4.1.1.2 item 3)
Policy/parameters except for the mapping of V2X service types to Tx
Profiles and the list of V2X services with Geographical Area(s)
that require privacy support. [0064] 6) Policy/parameters when NR
PC5 is selected: [0065] The mapping of V2X service types (e.g.
PSIDs or ITS-AIDS) to V2X frequencies with Geographical Area(s).
[0066] The mapping of Destination Layer-2 ID(s) and the V2X service
types, e.g. PSIDs or ITS-AIDs of the V2X application for broadcast.
[0067] The mapping of Destination Layer-2 ID(s) and the V2X service
types, e.g. PSIDs or ITS-AIDs of the V2X application for groupcast.
[0068] The mapping of default Destination Layer-2 ID(s) for initial
signalling to establish unicast connection and the V2X service
types, e.g. PSIDs or ITS-AIDS of the V2X application. [0069] NOTE
3: The same default Destination Layer-2 ID for unicast initial
signalling can be mapped to more than one V2X service types. In the
case where different V2X services are mapped to distinct default
Destination Layer-2 IDs, when the UE intends to establish a single
unicast link that can be used for more than one V2X service types,
the UE can select any of the default Destination Layer-2 IDs to use
for the initial signalling. [0070] PC5 QoS mapping configuration:
[0071] Input from V2X application layer: [0072] V2X service type
(e.g. PSID or ITS-AID). [0073] (Optional) V2X Application
Requirements for the V2X service type, e.g. priority requirement,
reliability requirement, delay requirement, range requirement.
[0074] NOTE 4: Details of V2X Application Requirements for the V2X
service type is up to implementation and out of scope of this
specification. [0075] Output: [0076] PC5 QoS parameters defined in
clause 5.4.2 (i.e. PQI and conditionally other parameters such as
MFBR/GFBR, etc.). [0077] AS layer configurations (see TS 38.331
[15]), e.g. the mapping of PC5 QoS profile(s) to radio bearer(s),
when the UE is "not served by E-UTRA" and "not served by NR".
[0078] The PC5 QoS profile contains PC5 QoS parameters described in
clause 5.4.2, and value for the QoS characteristics regarding
Priority Level, Averaging Window, Maximum Data Burst Volume if
default value is not used as defined in Table 5.4.4-1. [0079] 7)
Validity timer indicating the expiration time of the V2X
Policy/Parameter.
[0080] The above parameter sets from bullet 2) to 6) may be
configured in the UE through the V1 reference point by the V2X
Application Server.
[ . . . ]
5.2.1.4 Unicast Mode Communication Over PC5 Reference Point
[0081] Unicast mode of communication is only supported over NR
based PC5 reference point. FIG. 5.2.1.4-1 illustrates an example of
PC5 unicast links.
[0082] [FIG. 5.2.1.4-1 of 3GPP TS 23.287 V16.2.0, entitled "Example
of PC5 Unicast Links", is reproduced as FIG. 5]
[0083] The following principles apply when the V2X communication is
carried over PC5 unicast link: [0084] A PC5 unicast link between
two UEs allows V2X communication between one or more pairs of peer
V2X services in these UEs. All V2X services in the UE using the
same PC5 unicast link use the same Application Layer ID. [0085]
NOTE 1: An Application Layer ID can change in time as described in
clauses 5.6.1.1 and 6.3.3.2, due to privacy. This does not cause a
re-establishment of a PC5 unicast link. The UE triggers a Link
Identifier Update procedure as specified in clause 6.3.3.2. [0086]
One PC5 unicast link supports one or more V2X service types (e.g.
PSIDs or ITS-AIDS) if these V2X service types are at least
associated with the pair of peer Application Layer IDs for this PC5
unicast link. For example, as illustrated in FIG. 5.2.1.4-1, UE A
and UE B have two PC5 unicast links, one between peer Application
Layer ID 1/UE A and Application Layer ID 2/UE B and one between
peer Application Layer ID 3/UE A and Application Layer ID 4/UE B.
[0087] NOTE 2: A source UE is not required to know whether
different target Application Layer IDs over different PC5 unicast
links belong to the same target UE. [0088] A PC5 unicast link
supports V2X communication using a single network layer protocol
e.g. IP or non-IP. [0089] A PC5 unicast link supports per-flow QoS
model as specified in clause 5.4.1.
[0090] When the Application layer in the UE initiates data transfer
for a V2X service type which requires unicast mode of communication
over PC5 reference point: [0091] the UE shall reuse an existing PC5
unicast link if the pair of peer Application Layer IDs and the
network layer protocol of this PC5 unicast link are identical to
those required by the application layer in the UE for this V2X
service, and modify the existing PC5 unicast link to add this V2X
service type as specified in clause 6.3.3.4; otherwise [0092] the
UE shall trigger the establishment of a new PC5 unicast link as
specified in clause 6.3.3.1.
[0093] After successful PC5 unicast link establishment, UE A and UE
B use the same pair of Layer-2 IDs for subsequent PC5-S signalling
message exchange and V2X service data transmission as specified in
clause 5.6.1.4. The V2X layer of the transmitting UE indicates to
the AS layer whether a transmission is for a PC5-S signalling
message (i.e. Direct Communication Request/Accept, Link Identifier
Update Request/Response/Ack, Disconnect Request/Response, Link
Modification Request/Accept) or V2X service data.
[0094] For every PC5 unicast link, a UE self-assigns a distinct PC5
Link Identifier that uniquely identifies the PC5 unicast link in
the UE for the lifetime of the PC5 unicast link. Each PC5 unicast
link is associated with a Unicast Link Profile which includes:
[0095] V2X service type(s) (e.g. PSID(s) or ITS-AID(s)); and [0096]
Application Layer ID and Layer-2 ID of UE A; and [0097] Application
Layer ID and Layer-2 ID of UE B; and [0098] network layer protocol
used on the PC5 unicast link; and [0099] for each V2X service type,
a set of PC5 QoS Flow Identifier(s) (PFI(s)). Each PFI is
associated with QoS parameters (i.e. PQI).
[0100] For privacy reason, the Application Layer IDs and Layer-2
IDs may change as described in clauses 5.6.1.1 and 6.3.3.2 during
the lifetime of the PC5 unicast link and, if so, shall be updated
in the Unicast Link Profile accordingly. The UE uses PC5 Link
Identifier to indicate the PC5 unicast link to V2X Application
layer, therefore V2X Application layer identifies the corresponding
PC5 unicast link even if there are more than one unicast link
associated with one V2X service type (e.g. the UE establishes
multiple unicast links with multiple UEs for a same V2X service
type).
[0101] The Unicast Link Profile shall be updated accordingly after
a Layer-2 link modification for an established PC5 unicast link as
specified in clause 6.3.3.4 or Layer-2 link identifier update as
specified in clause 6.3.3.2.
[0102] V2X Service Info and QoS Info are carried in PC5-S
signalling messages and exchanged between two UEs as specified in
clause 6.3.3. Based on the exchanged information, PFI is used to
identify V2X service. When the receiving UE receives V2X service
data over the established PC5 unicast link, the receiving UE
determines the appropriate V2X service based on the PFI to forward
the received V2X service data to the upper layer.
[0103] Upon receiving an indication from the AS layer that the
PC5-RRC connection was released due to RLF, the V2X layer in the UE
locally releases the PC5 unicast link associated with this PC5-RRC
connection. The AS layer uses PC5 Link Identifier to indicate the
PC5 unicast link whose PC5-RRC connection was released.
[0104] When the PC5 unicast link has been released as specified in
clause 6.3.3.3, the V2X layer of each UE for the PC5 unicast link
informs the AS layer that the PC5 unicast link has been released.
The V2X layer uses PC5 Link Identifier to indicate the released
unicast link.
[ . . . ]
5.6.1.4 Identifiers for Unicast Mode V2X Communication Over PC5
Reference Point
[0105] For unicast mode of V2X communication over PC5 reference
point, the destination Layer-2 ID used depends on the communication
peer. The Layer-2 ID of the communication peer, identified by the
Application Layer ID, may be discovered during the establishment of
the PC5 unicast link, or known to the UE via prior V2X
communications, e.g. existing or prior unicast link to the same
Application Layer ID, or obtained from application layer service
announcements. The initial signalling for the establishment of the
PC5 unicast link may use the known Layer-2 ID of the communication
peer, or a default destination Layer-2 ID associated with the V2X
service type (e.g. PSID/ITS-AID) configured for PC5 unicast link
establishment, as specified in clause 5.1.2.1. During the PC5
unicast link establishment procedure, Layer-2 IDs are exchanged,
and should be used for future communication between the two UEs, as
specified in clause 6.3.3.1.
[0106] The Application Layer ID is associated with one or more V2X
applications within the UE. If UE has more than one Application
Layer IDs, each Application Layer ID of the same UE may be seen as
different UE's Application Layer ID from the peer UE's
perspective.
[0107] The UE maintains a mapping between the Application Layer IDs
and the source Layer-2 IDs used for the PC5 unicast links, as the
V2X application layer does not use the Layer-2 IDs. This allows the
change of source Layer-2 ID without interrupting the V2X
applications.
[0108] When Application Layer IDs change, the source Layer-2 ID(s)
of the PC5 unicast link(s) shall be changed if the link(s) was used
for V2X communication with the changed Application Layer IDs.
[0109] Based on privacy configuration as specified in clause
5.1.2.1, the update of the new identifiers of a source UE to the
peer UE for the established unicast link may cause the peer UE to
change its Layer-2 ID and optionally IP address/prefix if IP
communication is used as defined in clause 6.3.3.2.
[0110] A UE may establish multiple PC5 unicast links with a peer UE
and use the same or different source Layer-2 IDs for these PC5
unicast links.
6.1 Control and User Plane Stacks
6.1.1 User Plane for NR PC5 Reference Point Supporting V2X
Services
[0111] FIG. 6.1.1-1 depicts a user plane for NR PC5 reference
point, i.e. PC5 User Plane Protocol stack.
[0112] [FIG. 6.1.1-1 of 3GPP TS 23.287 V16.2.0, Entitled "User
Plane for NR PC5 Reference Point", is Reproduced as FIG. 6]
[0113] IP and Non-IP PDCP SDU types are supported for the V2X
communication over PC5 reference point.
[0114] For IP PDCP SDU type, only IPv6 is supported. The IP address
allocation and configuration are as defined in clause 5.6.1.1.
[0115] The Non-IP PDCP SDU contains a Non-IP Type header, which
indicates the V2X message family used by the application layer,
e.g. IEEE 1609 family's WSMP [18], ISO defined FNTP [19]. [0116]
NOTE: The Non-IP Type header and allowed values are defined in TS
24.587 [24].
[0117] The packets from V2X application layer are handled by the
V2X layer before transmitting them to the AS layer, e.g. V2X layer
maps the IP/Non IP packets to PC5 QoS Flow and marks the
corresponding PFI.
6.1.2 Control Plane for NR PC5 Reference Point Supporting V2X
Services
[0118] Editor's note: Whether PC5-S messages are carried in PC5 RRC
signalling depends on RAN decision.
[0119] FIG. 6.1.2-1 depicts a control plane for NR PC5 reference
point, i.e. PC5 Signalling Protocol stack.
[FIG. 6.1.2-1 of 3GPP TS 23.287 V16.2.0, Entitled "Control Plane
for NR PC5 Reference Point", is Reproduced as FIG. 7]
[0120] [ . . . ]
6.3.3 Unicast Mode V2X Communication Over PC5 Reference Point
6.3.3.1 Layer-2 Link Establishment Over PC5 Reference Point
[0121] To perform unicast mode of V2X communication over PC5
reference point, the UE is configured with the related information
as described in clause 5.1.2.1.
[0122] FIG. 6.3.3.1-1 shows the layer-2 link establishment
procedure for unicast mode of V2X communication over PC5 reference
point.
[FIG. 6.3.3.1-1 of 3GPP TS 23.287 V16.2.0, Entitled "Layer-2 Link
Establishment Procedure", is Reproduced as FIG. 8]
[0123] 1. The UE(s) determine the destination Layer-2 ID for
signalling reception for PC5 unicast link establishment as
specified in clause 5.6.1.4. The destination Layer-2 ID is
configured with the UE(s) as specified in clause 5.1.2.1. [0124] 2.
The V2X application layer in UE-1 provides application information
for PC5 unicast communication. The application information includes
the V2X service type(s) (e.g. PSID(s) or ITS-AID(s)) of the V2X
application and the initiating UE's Application Layer ID. The
target UE's Application Layer ID may be included in the application
information. [0125] The V2X application layer in UE-1 may provide
V2X Application Requirements for this unicast communication. UE-1
determines the PC5 QoS parameters and PFI as specified in clause
5.4.1.4. [0126] If UE-1 decides to reuse the existing PC5 unicast
link as specified in clause 5.2.1.4, the UE triggers Layer-2 link
modification procedure as specified in clause 6.3.3.4. [0127] 3.
UE-1 sends a Direct Communication Request message to initiate the
unicast layer-2 link establishment procedure. The Direct
Communication Request message includes: [0128] Source User Info:
the initiating UE's Application Layer ID (i.e. UE-Vs Application
Layer ID). [0129] If the V2X application layer provided the target
UE's Application Layer ID in step 2, the following information is
included: [0130] Target User Info: the target UE's Application
Layer ID (i.e. UE-2's Application Layer ID). [0131] V2X Service
Info: the information about V2X Service(s) requesting Layer-2 link
establishment (e.g. PSID(s) or ITS-AID(s)). [0132] Security
Information: the information for the establishment of security.
[0133] NOTE 1: The Security Information and the necessary
protection of the Source User Info and Target User Info are defined
by SA WG3. [0134] The source Layer-2 ID and destination Layer-2 ID
used to send the Direct Communication Request message are
determined as specified in clauses 5.6.1.1 and 5.6.1.4. The
destination Layer-2 ID may be broadcast or unicast Layer-2 ID. When
unicast Layer-2 ID is used, the Target User Info shall be included
in the Direct Communication Request message. [0135] UE-1 sends the
Direct Communication Request message via PC5 broadcast or unicast
using the source Layer-2 ID and the destination Layer-2 ID. [0136]
4. Security with UE-1 is established as below: [0137] 4a. If the
Target User Info is included in the Direct Communication Request
message, the target UE, i.e. UE-2, responds by establishing the
security with UE-1. [0138] 4b. If the Target User Info is not
included in the Direct Communication Request message, the UEs that
are interested in using the announced V2X Service(s) over a PC5
unicast link with UE-1 responds by establishing the security with
UE-1. [0139] NOTE 2: The signalling for the Security Procedure is
defined by SA WG3. [0140] When the security protection is enabled,
UE-1 sends the following information to the target UE: [0141] If IP
communication is used: [0142] IP Address Configuration: For IP
communication, IP address configuration is required for this link
and indicates one of the following values: "IPv6 Router" if IPv6
address allocation mechanism is supported by the initiating UE,
i.e., acting as an IPv6 Router; or "IPv6 address allocation not
supported" if IPv6 address allocation mechanism is not supported by
the initiating UE. [0143] Link Local IPv6 Address: a link-local
IPv6 address formed locally based on RFC 4862 [21] if UE-1 does not
support the IPv6 IP address allocation mechanism, i.e. the IP
Address Configuration indicates "IPv6 address allocation not
supported". [0144] QoS Info: the information about PC5 QoS Flow(s).
For each PC5 QoS Flow, the PFI and the corresponding PC5 QoS
parameters (i.e. PQI and conditionally other parameters such as
MFBR/GFBR, etc.). [0145] The source Layer-2 ID used for the
security establishment procedure is determined as specified in
clauses 5.6.1.1 and 5.6.1.4. The destination Layer-2 ID is set to
the source Layer-2 ID of the received Direct Communication Request
message. [0146] Upon receiving the security establishment procedure
messages, UE-1 obtains the peer UE's Layer-2 ID for future
communication, for signalling and data traffic for this unicast
link. [0147] 5. A Direct Communication Accept message is sent to
UE-1 by the target UE(s) that has successfully established security
with UE-1: [0148] 5a. (UE oriented Layer-2 link establishment)
lithe Target User Info is included in the Direct Communication
Request message, the target UE, i.e. UE-2 responds with a Direct
Communication Accept message if the Application Layer ID for UE-2
matches. [0149] 5b. (V2X Service oriented Layer-2 link
establishment) lithe Target User Info is not included in the Direct
Communication Request message, the UEs that are interested in using
the announced V2X Service(s) respond to the request by sending a
Direct Communication Accept message (UE-2 and UE-4 in FIG.
6.3.3.1-1). [0150] The Direct Communication Accept message
includes: [0151] Source User Info: Application Layer ID of the UE
sending the Direct Communication Accept message. [0152] QoS Info:
the information about PC5 QoS Flow(s). For each PC5 QoS Flow, the
PFI and the corresponding PC5 QoS parameters requested by UE-1
(i.e. PQI and conditionally other parameters such as MFBR/GFBR,
etc). [0153] If IP communication is used: [0154] IP Address
Configuration: For IP communication, IP address configuration is
required for this link and indicates one of the following values:
"IPv6 Router" if IPv6 address allocation mechanism is supported by
the target UE, i.e., acting as an IPv6 Router; or "IPv6 address
allocation not supported" if IPv6 address allocation mechanism is
not supported by the target UE. [0155] Link Local IPv6 Address: a
link-local IPv6 address formed locally based on RFC 4862 [21] if
the target UE does not support the IPv6 IP address allocation
mechanism, i.e. the IP Address Configuration indicates "IPv6
address allocation not supported", and UE-1 included a link-local
IPv6 address in the Direct Communication Request message. The
target UE shall include a non-conflicting link-local IPv6 address.
[0156] If both UEs (i.e. the initiating UE and the target UE)
selected to use link-local IPv6 address, they shall disable the
duplicate address detection defined in RFC 4862 [21]. [0157] NOTE
3: When either the initiating UE or the target UE indicates the
support of IPv6 router, corresponding address configuration
procedure would be carried out after the establishment of the layer
2 link, and the link-local IPv6 addresses are ignored. [0158] The
V2X layer of the UE that established PC5 unicast link passes the
PC5 Link Identifier assigned for the unicast link and the PC5
unicast link related information down to the AS layer. The PC5
unicast link related information includes Layer-2 ID information
(i.e. source Layer-2 ID and destination Layer-2 ID). This enables
the AS layer to maintain the PC5 Link Identifier together with the
PC5 unicast link related information. [0159] 6. V2X service data is
transmitted over the established unicast link as below: [0160] The
PC5 Link Identifier, and PFI are provided to the AS layer, together
with the V2X service data. [0161] Optionally in addition, the
Layer-2 ID information (i.e. source Layer-2 ID and destination
Layer-2 ID) is provided to the AS layer. [0162] NOTE 4: It is up to
UE implementation to provide the Layer-2 ID information to the AS
layer. [0163] UE-1 sends the V2X service data using the source
Layer-2 ID (i.e. UE-1's Layer-2 ID for this unicast link) and the
destination Layer-2 ID (i.e. the peer UE's Layer-2 ID for this
unicast link). [0164] NOTE 5: PC5 unicast link is bi-directional,
therefore the peer UE of UE-1 can send the V2X service data to UE-1
over the unicast link with UE-1.
[0165] 3GPP TS 24.587 specifies Stage 3 PC5 unicast link
establishment procedure as follows:
6.1.2.2 PC5 Unicast Link Establishment Procedure
6.1.2.2.1 General
[0166] The PC5 unicast link establishment procedure is used to
establish a PC5 unicast link between two UEs. The UE sending the
request message is called the "initiating UE" and the other UE is
called the "target UE". [0167] Editor's note: The details about
security procedure defined by SA3 are FFS. [0168] Editor's note:
The details of the IEs of the following messages are FFS.
6.1.2.2.2 PC5 Unicast Link Establishment Procedure Initiation by
Initiating UE
[0168] [0169] Editor's note: This section needs to be revisited
after SA3 have determined the full set of security requirements for
unicast link establishment.
[0170] The initiating UE shall meet the following pre-conditions
before initiating this procedure: [0171] a) a request from upper
layers to transmit the packet for V2X service over PC5; [0172] b)
the link layer identifier for the initiating UE (i.e. layer 2 ID
used for unicast communication) is available (e.g. pre-configured
or self-assigned); [0173] c) the link layer identifier for the
unicast initial signaling (i.e. destination layer 2 ID used for
unicast initial signaling) is available to the initiating UE (e.g.
pre-configured, obtained as specified in clause 5.2.3 or known via
prior V2X communication); [0174] d) the initiating UE is either
authorised for V2X communication over PC5 in NR in the serving
PLMN, or has a valid authorization for V2X communication over PC5
in NR when not served by E-UTRAN and not served by NR; and [0175]
e) there is no existing PC5 unicast link for the pair of peer
application layer IDs and the network layer protocol of this PC5
unicast link are identical to those required by the upper layer in
the initiating UE for this V2X service.
[0176] In order to initiate the PC5 unicast link establishment
procedure, the initiating UE shall create a DIRECT LINK
ESTABLISHMENT REQUEST message. The initiating UE: [0177] a) shall
include the source user info set to the initiating UE's application
layer ID received from upper layers; [0178] b) shall include the
V2X service identifier received from upper layer; [0179] c) may
include the target user info set to the target UE's application
layer ID if received from upper layers; and [0180] d) shall include
the security establishment information. [0181] Editor's note: The
parameters in the security establishment information will be
defined by SA3.
[0182] After the DIRECT LINK ESTABLISHMENT REQUEST message is
generated, the initiating UE shall pass this message to the lower
layers for transmission along with the initiating UE's Layer 2 ID
for unicast communication and the destination layer 2 ID used for
unicast initial signaling, and start timer T5000. The UE shall not
send a new DIRECT LINK ESTABLISHMENT REQUEST message to the same
target UE identified by the same application layer ID while timer
T5000 is running.
[0183] [FIG. 6.1.2.2.2 of 3GPP TS 24.587 V16.0.0, Entitled "PC5
Unicast Link Establishment Procedure", is Reproduced as FIG. 9]
6.1.2.2.3 PC5 Unicast Link Establishment Procedure Accepted by the
Target UE
[0184] Upon receipt of a DIRECT LINK ESTABLISHMENT REQUEST message,
the target UE shall assign a layer-2 ID for this PC5 unicast link
and store this assigned layer-2 ID and the source layer 2 ID used
in the transport of this message provided by the lower layers. This
pair of layer-2 IDs is associated with a PC5 unicast link
context.
If:
[0185] a) the target user info IE is included in the DIRECT LINK
ESTABLISHMENT REQUEST message and this IE includes the target UE's
application layer ID; or [0186] b) the target user info IE is not
included in the DIRECT LINK ESTABLISHMENT REQUEST message and the
target UE is interested in the V2X service identified by the V2X
service identifier in the DIRECT LINK ESTABLISHMENT REQUEST
message; then the target UE shall either identify an existing
security context with the initiating UE, or establish a new
security context by performing one or more PC5 unicast link
authentication procedures as specified in clause 6.1.2.6, and
performing the PC5 unicast link security mode control procedure as
specified in clause 6.1.2.7.
[0187] Upon successful completion of the PC5 unicast link security
mode control procedure, in order to determine whether the DIRECT
LINK ESTABLISHMENT REQUEST message can be accepted or not, in case
of IP communication, the target UE checks whether there is at least
one common IP address configuration option supported by both the
initiating UE and the target UE.
[0188] If the target UE accepts the PC5 unicast link establishment
procedure, the target UE shall create a DIRECT LINK ESTABLISHMENT
ACCEPT message. The target UE: [0189] a) shall include the source
user info set to the target UE's application layer ID received from
upper layers; [0190] b) shall include a PQFI and the corresponding
PC5 QoS parameters; [0191] c) may include an IP address
configuration IE set to one of the following values if IP
communication is used: [0192] 1) "IPv6 router" if only IPv6 address
allocation mechanism is supported by the target UE, i.e. acting as
an IPv6 router; or [0193] 2) "IPv6 address allocation not
supported" if IPv6 address allocation mechanism is not supported by
the target UE; [0194] d) may include a link local IPv6 address IE
formed locally based on IETF RFC 4862 [16] if IP address
configuration IE is set to "IPv6 address allocation not supported"
and the received DIRECT LINK ESTABLISHMENT REQUEST message included
a link local IPv6 address IE.
6.1.2.2.4 PC5 Unicast Link Establishment Procedure Completion by
the Initiating UE
[0195] Upon receipt of the DIRECT LINK ESTABLISHMENT ACCEPT
message, the initiating UE shall stop timer T5000 and store the
source layer-2 ID and the destination Layer-2 ID used in the
transport of this message provided by the lower layers. This pair
of layer-2 IDs shall be associated with a PC5 unicast link context.
From this time onward the initiating UE shall use the established
link for V2X communication over PC5 and additional PC5 signalling
messages to the target UE.
6.1.2.2.5 PC5 Unicast Link Establishment Procedure not Accepted by
the Target UE
[0196] If the DIRECT LINK ESTABLISHMENT REQUEST message cannot be
accepted, the target UE shall send a DIRECT LINK ESTABLISHMENT
REJECT message. The DIRECT LINK ESTABLISHMENT REJECT message
contains a PC5 signalling protocol cause IE set to one of the
following cause values: [0197] #1 direct communication to the
target UE not allowed; [0198] #3 conflict of Layer 2 ID for unicast
communication is detected; [0199] #5 lack of resources for proposed
link; or [0200] #111 protocol error, unspecified.
[0201] If the target UE is not allowed to accept this request e.g.
based on operator policy or service authorisation provisioning, the
target UE shall send a DIRECT LINK ESTABLISHMENT REJECT message
containing PC5 signalling protocol cause value #1 "direct
communication to the target UE not allowed".
[0202] For a received DIRECT LINK ESTABLISHMENT REQUEST message
from a Layer 2 ID (for unicast communication), if the target UE
already has an existing link established to the UE known to use
this Layer 2 ID or is currently processing a DIRECT LINK
ESTABLISHMENT REQUEST message from the same Layer 2 ID, but with
user info different from the user info IE included in this new
incoming message, the target UE shall send a DIRECT LINK
ESTABLISHMENT REJECT message containing PC5 signalling protocol
cause value #3 "conflict of Layer 2 ID for unicast communication is
detected".
[0203] If the PC5 unicast link establishment fails due to the
congestion problems or other temporary lower layer problems causing
resource constraints, the target UE shall send a DIRECT LINK
ESTABLISHMENT REJECT message containing PC5 signalling protocol
cause value #5 "lack of resources for proposed link".
[0204] For other reasons that causing the failure of link
establishment, the target UE shall send a DIRECT LINK ESTABLISHMENT
REJECT message containing PC5 signalling protocol cause value #111
"protocol error, unspecified".
[0205] Upon receipt of the DIRECT LINK ESTABLISHMENT REJECT
message, the initiating UE shall stop timer T5000 and abort the PC5
unicast link establishment procedure. If the PC5 signalling
protocol cause value in the DIRECT LINK ESTABLISHMENT REJECT
message is #1 "direct communication to the target UE not allowed"
or #5 "lack of resources for proposed link", then the UE shall not
attempt to start PC5 unicast link establishment with the same
target UE at least for a time period T. [0206] NOTE: The length of
time period T is UE implementation specific and can be different
for the case when the UE receives PC5 signalling protocol cause
value #1 "direct communication to the target UE not allowed" or
when the UE receives PC5 signalling protocol cause value #5 "lack
of resources for proposed link".
6.1.2.2.6 Abnormal Cases
6.1.2.2.6.1 Abnormal Cases at the Initiating UE
[0207] If timer T5000 expires, the initiating UE shall retransmit
the DIRECT LINK ESTABLISHMENT REQUEST message and restart timer
T5000. After reaching the maximum number of allowed
retransmissions, the initiating UE shall abort the PC5 unicast link
establishment procedure and may notify the upper layer that the
target UE is unreachable. [0208] NOTE: The maximum number of
allowed retransmissions is UE implementation specific.
[0209] If the need to establish a link no longer exists before the
procedure is completed, the initiating UE shall abort the
procedure.
6.1.2.2.6.2 Abnormal Cases at the Target UE
[0210] For a received DIRECT LINK ESTABLISHMENT REQUEST message
from a source Layer 2 ID (for unicast communication), if the target
UE already has an existing link established to the UE known to use
this source Layer 2 ID and the new request contains an identical
source user info as the known user, the UE shall process the new
request. However, the target UE shall only delete the existing link
context after the new link establishment procedure succeeds.
[0211] 3GPP TS 38.331 specifies Radio Resource Control (RRC)
reconfiguration, UE capability information, sidelink UE
information, and sidelink Data Radio Bearer (DRB) establishment as
follows:
5.3.5 RRC Reconfiguration
[0212] [ . . . ]
5.3.5.3 Reception of an RRCReconfiguration by the UE
[0213] The UE shall perform the following actions upon reception of
the RRCReconfiguration, or upon execution of the conditional
configuration (CHO or CPC):
[ . . . ] [0214] 1> if the RRCReconfiguration message includes
the sl-ConfigDedicatedNR: [0215] 2> perform the sidelink
dedicated configuration procedure as specified in 5.3.5.8; [ . . .
]
5.3.5.14 Sidelink Dedicated Configuration
[0216] The UE shall: [0217] 1> if sl-FreqInfoToAddModList is
included in sl-ConfigDedicatedNR within RRCReconfiguration: [0218]
2> if configured to receive NR sidelink communication: [0219]
3> use the resource pool indicated by sl-RxPool for NR sidelink
communication reception, as specified in 5.8.7; [0220] 2> if
configured to transmit NR sidelink communication: [0221] 3> use
the resource pool(s) indicated by sl-TxPoolSelectedNormal,
sl-TxPoolScheduling or sl-TxPoolExceptional for NR sidelink
communication transmission, as specified in 5.8.8; [0222] 2>
perform CBR measurement on the transmission resource pools by
sl-TxPoolSelectedNormal, sl-TxPoolScheduling or
sl-TxPoolExceptional for NR sidelink communication transmission, as
specified in 5.5.3.1; [0223] 2> use the synchronization
configuration parameters for NR sidelink communication on
frequencies included in sl-FreqInfoToAddModList, as specified in
5.8.5; [0224] 1> if sl-FreqInfoToReleaseList is included in
sl-ConfigDedicatedNR within RRCReconfiguration: [0225] 2> for
each entry included in the received sl-FreqInfoToReleaseList that
is part of the current UE configuration: [0226] 3> release the
related configurations from the stored NR sidelink communication
configurations; [0227] 1> if sl-RadioBearerToReleaseList is
included in sl-ConfigDedicatedNR within RRCReconfiguration: [0228]
2> perform sidelink DRB release as specified in 5.8.9.1.4;
[0229] 1> if sl-RadioBearerToAddModList is included in
sl-ConfigDedicatedNR within RRCReconfiguration: [0230] 2>
perform sidelink DRB addition/modification as specified in
5.8.9.1.5; [0231] 1> if sl-ScheduledConfig is included in
sl-ConfigDedicatedNR within RRCReconfiguration: [0232] 2>
configure the MAC entity parameters, which are to be used for NR
sidelink communication, in accordance with the received
sl-ScheduledConfig; [0233] 1> if sl-UE-SelectedConfig is
included in sl-ConfigDedicatedNR within RRCReconfiguration: [0234]
2> configure the parameters, which are to be used for NR
sidelink communication, in accordance with the received
sl-UE-SelectedConfig; [0235] 1> if sl-MeasConfigInfoToReleaseUst
is included in sl-ConfigDedicatedNR within RRCReconfiguration:
[0236] 2> for each entry included in the received
sl-MeasConfigInfoToReleaseUst that is part of the current UE
configuration: [0237] 3> release the related configurations from
the stored NR sidelink measurement configuration information;
[0238] 1> if sl-MeasConfigInfoToAddModList is included in
sl-ConfigDedicatedNR within RRCReconfiguration: [0239] 2> for
each entry included in the received sl-MeasConfigInfoToAddModList
that is part of the current stored NR sidelink measurement
configuration: [0240] 3> update the stored NR sidelink
measurement configuration information; [0241] 2> for each entry
included in the received sl-MeasConfigInfoToAddModList that is not
part of the current stored NR sidelink measurement configuration:
[0242] 3> store the NR sidelink measurement configuration. [ . .
. ]
5.6.1 UE Capability Transfer
5.6.1.1 General
[0243] This clause describes how the UE compiles and transfers its
UE capability information upon receiving a UECapabilityEnquiry from
the network.
[FIG. 5.6.1.1-1 of 3GPP TS 38.331 V16.0.0, Entitled "UE Capability
Transfer", is Reproduced as FIG. 10]
5.6.1.2 Initiation
[0244] The network initiates the procedure to a UE in RRC_CONNECTED
when it needs (additional) UE radio access capability information.
The network should retrieve UE capabilities only after AS security
activation. Network does not forward UE capabilities that were
retrieved before AS security activation to the CN.
5.6.1.3 Reception of the UECapabilityEnquiry by the UE
[0245] The UE shall set the contents of UECapabilityInformation
message as follows: [0246] 1> if the
ue-CapabilityRAT-RequestList contains a UE-CapabilityRAT-Request
with rat-Type set to nr: [0247] 2> include in the
ue-CapabilityRAT-ContainerList a UE-CapabilityRAT-Container of the
type UE-NR-Capability and with the rat-Type set to nr; [0248] 2>
include the sup portedBandCombinationList, featuresets and
featuresetCombinations as specified in clause 5.6.1.4; [0249] 1>
if the ue-CapabilityRAT-RequestList contains a
UE-CapabilityRAT-Request with rat-Type set to eutra-nr: [0250]
2> if the UE supports (NG)EN-DC or NE-DC: [0251] 3> include
in the ue-CapabilityRAT-ContainerList a UE-CapabilityRAT-Container
of the type UE-MRDC-Capability and with the rat-Type set to
eutra-nr; [0252] 3> include the sup portedBandCombinationList
and featureSetCombinations as specified in clause 5.6.1.4; [0253]
1> if the ue-CapabilityRAT-RequestList contains a
UE-CapabilityRAT-Request with rat-Type set to eutra: [0254] 2>
if the UE supports E-UTRA: [0255] 3> include in the
ue-CapabilityRAT-ContainerList a ue-CapabilityRAT-Container of the
type UE-EUTRA-Capability and with the rat-Type set to eutra as
specified in TS 36.331 [10], clause 5.6.3.3, according to the
capabilityRequestFilter, if received; [0256] 1> if the
ue-CapabilityRAT-RequestList contains a UE-CapabilityRAT-Request
with rat-Type set to utra-fdd: [0257] 2> if the UE supports
UTRA-FDD: [0258] 3> include the UE radio access capabilities for
UTRA-FDD within a ue-CapabilityRAT-Container and with the rat-Type
set to utra-fdd; [0259] 1> if the RRC message segmentation is
enabled based on the field rrc-SegAllowed received, and the encoded
RRC message is larger than the maximum supported size of a PDCP SDU
specified in TS 38.323 [5]: [0260] 2> initiate the UL message
segment transfer procedure as specified in clause 5.7.7; [0261]
1> else: [0262] 2> submit the UECapabilityInformation message
to lower layers for transmission, upon which the procedure ends. [
. . . ]
5.8.3 Sidelink UE Information for NR Sidelink Communication
5.8.3.1 General
[FIG. 5.8.3.1-1 of 3GPP TS 38.331 V16.0.0, Entitled "Sidelink UE
Information for NR Sidelink Communication", is Reproduced as FIG.
11]
[0263] The purpose of this procedure is to inform the network that
the UE is interested or no longer interested to receive NR sidelink
communication, as well as to request assignment or release of
transmission resource for NR sidelink communication and to report
parameters related to NR sidelink communication.
5.8.3.2 Initiation
[0264] A UE capable of NR sidelink communication that is in
RRC_CONNECTED may initiate the procedure to indicate it is
(interested in) receiving NR sidelink communication in several
cases including upon successful connection establishment or
resuming, upon change of interest, or upon change to a PCell
providing SIB12 including sl-ConfigCommonNR. A UE capable of NR
sidelink communication may initiate the procedure to request
assignment of dedicated resources for NR sidelink communication
transmission.
[0265] Upon initiating this procedure, the UE shall: [0266] 1>
if SIB12 including sl-ConfigCommonNR is provided by the PCell:
[0267] 2> ensure having a valid version of SIB12 for the PCell;
[0268] 2> if configured by upper layers to receive NR sidelink
communication on the frequency included in sl-FreqInfoList in SIB12
of the PCell: [0269] 3> if the UE did not transmit a
SidelinkUEInformationNR message since last entering RRC_CONNECTED
state; or [0270] 3> if since the last time the UE transmitted a
SidelinkUEInformationNR message the UE connected to a PCell not
providing SIB12 including sl-ConfigCommonNR; or [0271] 3> if the
last transmission of the SidelinkUEInformationNR message did not
include sl-RxInterestedFreqList; or if the frequency configured by
upper layers to receive NR sidelink communication on has changed
since the last transmission of the SidelinkUEInformationNR message:
[0272] 4> initiate transmission of the SidelinkUEInformationNR
message to indicate the NR sidelink communication reception
frequency of interest in accordance with 5.8.3.3; [0273] 2>
else: [0274] 3> if the last transmission of the
SidelinkUEInformationNR message included sl-RxInterestedFreqList:
[0275] 4> initiate transmission of the SidelinkUEInformationNR
message to indicate it is no longer interested in NR sidelink
communication reception in accordance with 5.8.3.3; [0276] 2> if
configured by upper layers to transmit NR sidelink communication on
the frequency included in sl-FreqInfoList in SIB12 of the PCell:
[0277] 3> if the UE did not transmit a SidelinkUEInformationNR
message since last entering RRC_CONNECTED state; or [0278] 3> if
since the last time the UE transmitted a SidelinkUEInformationNR
message the UE connected to a PCell not providing SIB12 including
sl-ConfigCommonNR; or [0279] 3> if the last transmission of the
SidelinkUEInformationNR message did not include
sl-TxResourceReqList; or if the information carried by the
sl-TxResourceReqList has changed since the last transmission of the
SidelinkUEInformationNR message: [0280] 4> initiate transmission
of the SidelinkUEInformationNR message to indicate the NR sidelink
communication transmission resources required by the UE in
accordance with 5.8.3.3; [0281] 2> else: [0282] 3> if the
last transmission of the SidelinkUEInformationNR message included
sl-TxResourceReqList: [0283] 4> initiate transmission of the
SidelinkUEInformationNR message to indicate it no longer requires
NR sidelink communication transmission resources in accordance with
5.8.3.3.
5.8.3.3 Actions Related to Transmission of SidelinkUEInformationNR
Message
[0284] The UE shall set the contents of the SidelinkUEInformationNR
message as follows: [0285] 1> if the UE initiates the procedure
to indicate it is (no more) interested to receive NR sidelink
communication or to request (configuration/release) of NR sidelink
communication transmission resources (i.e. UE includes all
concerned information, irrespective of what triggered the
procedure): [0286] 2> if SIB12 including sl-ConfigCommonNR is
provided by the PCell: [0287] 3> if configured by upper layers
to receive NR sidelink communication: [0288] 4> include
sl-RxInterestedFreqList and set it to the frequency for NR sidelink
communication reception; [0289] 3> if configured by upper layers
to transmit NR sidelink communication: [0290] 4> include
sl-TxResourceReqList and set its fields (if needed) as follows for
each destination for which it requests network to assign NR
sidelink communication resource: 5> set sl-DestinationIdentity
to the destination identity configured by upper layer for NR
sidelink communication transmission; 5> set sl-CastType to the
cast type of the associated destination identity configured by the
upper layer for the NR sidelink communication transmission; 5>
set sl-RLC-ModeIndication to include the RLC mode(s) and optionally
QoS profile(s) of the sidelink QoS flow(s) of the associated RLC
mode(s), if the associated bi-directional sidelink DRB has been
established due to the configuration by RRCReconfigurationSidelink;
5> set sl-Failure as rlf for the associated destination for the
NR sidelink communication transmission, if the sidelink RLF is
detected; 5> set sl-Failure as configFailure for the associated
destination for the NR sidelink communication transmission, if
RRCReconfigurationFailureSidelink is received as sidelink RRC
reconfiguration failure; 5> set sl-QoS-InfoList to include QoS
profile(s) of the sidelink QoS flow(s) of the associated
destination configured by the upper layer for the NR sidelink
communication transmission; 5> set sl-InterestedFreqList to
indicate the frequency for NR sidelink communication transmission;
5> set sl-TypeTxSyncList to the current synchronization
reference type used on the associated sl-InterestedFreqList for NR
sidelink communication transmission. [0291] 1> The UE shall
submit the SidelinkUEInformationNR message to lower layers for
transmission. [ . . . ]
5.8.9.1.5.2 Sidelink DRB Addition/Modification Operations
[0292] For the sidelink DRB, whose sidelink DRB addition conditions
are met as in sub-clause 5.8.9.1.5.1, the UE capable of NR sidelink
communication that is configured by upper layers to perform NR
sidelink communication shall: [0293] 1> for groupcast and
broadcast, or [0294] 1> for unicast, after receiving
RRCReconfigurationSidelink message (in case the addition is due to
the configuration by RRCReconfigurationSidelink), or after
receiving the RRCReconfigurationCompleteSidelink message (in case
the addition is due to the configuration by sl-ConfigDedicatedNR,
SIB12, SidelinkPreconfigNR or indicated by upper layers): [0295]
2> if an SDAP entity for NR sidelink communication associated
with the destination and the cast type of the sidelink DRB does not
exist: [0296] 3> establish an SDAP entity for NR sidelink
communication as specified in TS 37.324 [24] clause 5.1.1; [0297]
3> configure the SDAP entity in accordance with the
sl-SDAP-ConfigPC5 received in the RRCReconfigurationSidelink or
sl-SDAP-Config received in sl-ConfigDedicatedNR, SIB12,
SidelinkPreconfigNR, associated with the sidelink DRB; [0298] 2>
establish a PDCP entity for NR sidelink communication and configure
it in accordance with the sl-PDCP-ConfigPC5 received in the
RRCReconfigurationSidelink or sl-PDCP-Config received in
sl-ConfigDedicatedNR, SIB12, SidelinkPreconfigNR, associated with
the sidelink DRB; [0299] 2> establish a RLC entity for NR
sidelink communication and configure it in accordance with the
sl-RLC-ConfigPC5 received in the RRCReconfigurationSidelink or
sl-RLC-Config received in sl-ConfigDedicatedNR, SIB12,
SidelinkPreconfigNR, associated with sidelink DRB; [0300] 2> if
the RRCReconfigurationSidelink is received: [0301] 3> configure
the MAC entity with a logical channel in accordance with the
sl-MAC-LogicalChannelConfigPC5 received in the
RRCReconfigurationSidelink associated with the sidelink DRB, and
perform the sidelink UE information procedure in sub-clause 5.8.3
for unicast if need; [0302] 2> else: [0303] 3> configure the
MAC entity with a logical channel associated with the sidelink DRB,
by assigning a new logical channel identity, in accordance with the
sl-MAC-LogicalChannelConfig received in the sl-ConfigDedicatedNR,
SIB12, SidelinkPreconfigNR. [0304] NOTE 1: When a sidelink DRB
addition is due to the configuration by RRCReconfigurationSidelink,
it is up to UE implementation to select the sidelink DRB
configuration as necessary transmitting parameters for the sidelink
DRB, from the received sl-ConfigDedicatedNR (if in RRC_CONNECTED),
SIB12 (if in RRC_IDLE/INACTIVE), SidelinkPreconfigNR (if out of
coverage) with the same RLC mode as the one configured in
RRCReconfigurationSidelink.
[0305] For the sidelink DRB, whose sidelink DRB modification
conditions are met as in sub-clause 5.8.9.1.5.1, the UE capable of
NR sidelink communication that is configured by upper layers to
perform NR sidelink communication shall: [0306] 1> for groupcast
and broadcast, or [0307] 1> for unicast, after receiving
RRCReconfigurationSidelink message (in case the modification is due
to the configuration by RRCReconfigurationSidelink), or after
receiving the RRCReconfigurationCompleteSidelink message (in case
the modification is due to the configuration by
sl-ConfigDedicatedNR, SIB12 or SidelinkPreconfigNR): [0308] 2>
reconfigure the SDAP entity of the sidelink DRB, in accordance with
the sl-SDAP-ConfigPC5 received in the RRCReconfigurationSidelink or
sl-SDAP-Config received in sl-ConfigDedicatedNR, SIB12,
SidelinkPreconfigNR, if included; [0309] 2> reconfigure the PDCP
entity of the sidelink DRB, in accordance with the
sl-PDCP-ConfigPC5 received in the RRCReconfigurationSidelink or
sl-PDCP-Config received in sl-ConfigDedicatedNR, SIB12,
SidelinkPreconfigNR, if included; [0310] 2> reconfigure the RLC
entity of the sidelink DRB, in accordance with the sl-RLC-ConfigPC5
received in the RRCReconfigurationSidelink or sl-RLC-Config
received in sl-ConfigDedicatedNR, SIB12, SidelinkPreconfigNR, if
included; [0311] 2> reconfigure the logical channel of the
sidelink DRB, in accordance with the sl-MAC-LogicalChannelConfigPC5
received in the RRCReconfigurationSidelink or
sl-MAC-LogicalChannelConfig received in sl-ConfigDedicatedNR,
SIB12, SidelinkPreconfigNR, if included.
[0312] 3GPP R2-2005973 is a change request (CR) to 3GPP TS38.331
[3]. This CR adds sidelink UE capability information (i.e.
SidelinkParameters) in IE UE-NR-Capability in a
UECapabilityInformation message reported by a UE to gNB, introduces
sidelink UE capability transfer procedure between a UE and the peer
UE, and also includes the UECapabilityInformationSidelink message
received from the peer UE in a SidelinkUEinformationNR message
reported to gNB as follows:
5.8.3 Sidelink UE Information for NR Sidelink Communication
5.8.3.1 General
[0313] [FIG. 5.8.3.1-1 of 3GPP R2-2005973, Entitled "Sidelink UE
Information for NR Sidelink Communication", is Reproduced as FIG.
12]
[0314] The purpose of this procedure is to inform the network that
the UE is interested or no longer interested to receive NR sidelink
communication, as well as to request assignment or release of
transmission resource for NR sidelink communication and to report
parameters related to NR sidelink communication.
5.8.3.2 Initiation
[0315] A UE capable of NR sidelink communication that is in
RRC_CONNECTED may initiate the procedure to indicate it is
(interested in) receiving NR sidelink communication in several
cases including upon successful connection establishment or
resuming, upon change of interest, or upon change to a PCell
providing SIB12 including sl-ConfigCommonNR. A UE capable of NR
sidelink communication may initiate the procedure to request
assignment of dedicated resources for NR sidelink communication
transmission.
[0316] Upon initiating this procedure, the UE shall: [0317] 1>
if SIB12 including sl-ConfigCommonNR is provided by the PCell:
[0318] 2> ensure having a valid version of SIB12 for the PCell;
[0319] 2> if configured by upper layers to receive NR sidelink
communication on the frequency included in sl-FreqInfoList in SIB12
of the PCell: [0320] 3> if the UE did not transmit a
SidelinkUEInformationNR message since last entering RRC_CONNECTED
state; or [0321] 3> if since the last time the UE transmitted a
SidelinkUEInformationNR message the UE connected to a PCell not
providing SIB12 including sl-ConfigCommonNR; or 3> if the last
transmission of the SidelinkUEInformationNR message did not include
sl-RxInterestedFreqList; or if the frequency configured by upper
layers to receive NR sidelink communication on has changed since
the last transmission of the SidelinkUEInformationNR message:
[0322] 4> initiate transmission of the SidelinkUEInformationNR
message to indicate the NR sidelink communication reception
frequency of interest in accordance with 5.8.3.3; [0323] 2>
else: [0324] 3> if the last transmission of the
SidelinkUEInformationNR message included sl-RxInterestedFreqList:
[0325] 4> initiate transmission of the SidelinkUEInformationNR
message to indicate it is no longer interested in NR sidelink
communication reception in accordance with 5.8.3.3; [0326] 2> if
configured by upper layers to transmit NR sidelink communication on
the frequency included in sl-FreqInfoList in SIB12 of the PCell:
[0327] 3> if the UE did not transmit a SidelinkUEInformationNR
message since last entering RRC_CONNECTED state; or [0328] 3> if
since the last time the UE transmitted a SidelinkUEInformationNR
message the UE connected to a PCell not providing SIB12 including
sl-ConfigCommonNR; or [0329] 3> if the last transmission of the
SidelinkUEInformationNR message did not include
sl-TxResourceReqList; or if the information carried by the
sl-TxResourceReqList has changed since the last transmission of the
SidelinkUEInformationNR message: [0330] 4> initiate transmission
of the SidelinkUEInformationNR message to indicate the NR sidelink
communication transmission resources required by the UE in
accordance with 5.8.3.3; [0331] 2> else: [0332] 3> if the
last transmission of the SidelinkUEInformationNR message included
sl-TxResourceReqList: [0333] 4> initiate transmission of the
SidelinkUEInformationNR message to indicate it no longer requires
NR sidelink communication transmission resources in accordance with
5.8.3.3.
5.8.3.3 Actions Related to Transmission of SidelinkUEInformationNR
Message
[0334] The UE shall set the contents of the SidelinkUEInformationNR
message as follows: [0335] 1> if the UE initiates the procedure
to indicate it is (no more) interested to receive NR sidelink
communication or to request (configuration/release) of NR sidelink
communication transmission resources (i.e. UE includes all
concerned information, irrespective of what triggered the
procedure): [0336] 2> if SIB12 including sl-ConfigCommonNR is
provided by the PCell: [0337] 3> if configured by upper layers
to receive NR sidelink communication: [0338] 4> include
sl-RxInterestedFreqList and set it to the frequency for NR sidelink
communication reception; [0339] 3> if configured by upper layers
to transmit NR sidelink communication: [0340] 4> include
sl-TxResourceReqList and set its fields (if needed) as follows for
each destination for which it requests network to assign NR
sidelink communication resource: [0341] 5> set
sl-DestinationIdentity to the destination identity configured by
upper layer for NR sidelink communication transmission; [0342]
5> set sl-CastType to the cast type of the associated
destination identity configured by the upper layer for the NR
sidelink communication transmission; [0343] 5> set
sl-RLC-ModeIndication to include the RLC mode(s) and optionally QoS
profile(s) of the sidelink QoS flow(s) of the associated RLC
mode(s), if the associated bi-directional sidelink DRB has been
established due to the configuration by RRCReconfigurationSidelink;
[0344] 5> set sl-Failure as rlf for the associated destination
for the NR sidelink communication transmission, if the sidelink RLF
is detected; [0345] 5> set sl-Failure as configFailure for the
associated destination for the NR sidelink communication
transmission, if RRCReconfigurationFailureSidelink is received as
sidelink RRC reconfiguration failure; [0346] 5> set
sl-QoS-InfoList to include QoS profile(s) of the sidelink QoS
flow(s) of the associated destination configured by the upper layer
for the NR sidelink communication transmission; [0347] 5> set
sl-InterestedFreqList to indicate the frequency for NR sidelink
communication transmission; [0348] 5> set sl-TypeTxSyncList to
the current synchronization reference type used on the associated
sl-InterestedFreqList for NR sidelink communication transmission.
[0349] 5> set sl-CapabilityInformationSidelink to include
UECapabilityInformationSidelink message, if any, received from peer
UE. [0350] 1> The UE shall submit the SidelinkUEInformationNR
message to lower layers for transmission. [ . . . ]
5.8.9.2 Sidelink UE Capability Transfer
5.8.9.2.1 General
[0351] This clause describes how the UE compiles and transfers its
sidelink UE capability information for unicast to the initiating
UE.
[0352] [FIG. 5.8.9.2.1-1 of 3GPP R2-2005973, Entitled Sidelink UE
Capability Transfer", is Reproduced as FIG. 13]
5.8.9.2.2 Initiation
[0353] The UE may initiate the sidelink UE capability transfer
procedure upon indication from upper layer when it needs
(additional) UE radio access capability information.
5.8.9.2.3 Actions Related to Transmission of the
UECapabilityEnquirySidelink by the UE
[0354] The initiating UE shall set the contents of
UECapabilityEnquirySidelink message as follows: [0355] 1>
include in UE radio access capabilities for sidelink within
ueCapabilityInformationSidelink; [0356] NOTE: It is up to
initiating UE to decide whether ueCapabilityInformationSidelink
should be included. [0357] 1> set frequencyBandUstFilterSidelink
to include frequency bands for which the peer UE is requested to
provide supported bands and band combinations; [0358] 1> submit
the UECapabilityEnquirySidelink message to lower layers for
transmission.
5.8.9.2.4 Actions Related to Reception of the
UECapabilityEnquirySidelink by the UE
[0359] The peer UE shall set the contents of
UECapabilityInformationSidelink message as follows: [0360] 1>
include in UE radio access capabilities for sidelink within
ueCapabilityInformationSidelink; [0361] 1> compile a list of
"candidate band combinations" only consisting of bands included in
frequencyBandListFilter, and prioritized in the order of
frequencyBandUstFilterSidelink (i.e. first include band
combinations containing the first-listed band, then include
remaining band combinations containing the second-listed band, and
so on). [0362] 1> Include into
supportedBandCombinationListSidelink as many band combinations as
possible from the list of "candidate band combinations", starting
from the first entry; [0363] 1> submit the
UECapabilityInformationSidelink message to lower layers for
transmission.
[0364] SidelinkParameters
[0365] The IE SidelinkParameters is used to convey capabilities
related to NR sidelink communication.
TABLE-US-00001 SidelinkParameters information element -- ASN1START
-- TAG-SIDELINKPARAMETERS-START SidelinkParameters-r16 ::= SEQUENCE
{ rlc-ParametersSidelink-r16 RLC-ParametersSidelink-r16 OPTIONAL,
mac-ParametersSidelink-r16 MAC-ParametersSidelink-r16 OPTIONAL,
fdd-Add-UE-Sidelink-Capabilities-r16
UE-SidelinkCapabilityAddXDD-Mode-r16 OPTIONAL,
tdd-Add-UE-Sidelink-Capabilities-r16
UE-SidelinkCapabilityAddXDD-Mode-r16 OPTIONAL, nonCriticalExtension
SEQUENCE { } OPTIONAL } RLC-ParametersSidelink-r16 ::= SEQUENCE {
am-WithLongSN-Sidelink-r16 ENUMERATED {supported} OPTIONAL,
um-WithLongSN-Sidelink-r16 ENUMERATED {supported} OPTIONAL, ... }
MAC-ParametersSidelink-r16 ::= SEQUENCE {
mac-ParametersSidelinkCommon-r16 MAC-ParametersSidelinkCommon-r16
OPTIONAL, mac-ParametersSidelinkXDD-Diff-r16
MAC-ParametersSidelinkXDD-Diff-r16 OPTIONAL, ... }
UE-SidelinkCapabilityAddXDD-Mode-r16 ::= SEQUENCE {
mac-ParametersSidelinkXDD-Diff-r16
MAC-ParametersSidelinkXDD-Diff-r16 OPTIONAL }
MAC-ParametersSidelinkCommon-r16 ::= SEQUENCE {
lcp-RestrictionSidelink-r16 ENUMERATED {supported} OPTIONAL,
multipleConfiguredGrantsSidelink-r16 ENUMERATED {supported}
OPTIONAL, ... } MAC-ParametersSidelinkXDD-Diff-r16 ::= SEQUENCE {
multipleSR-ConfigurationsSidelink-r16 ENUMERATED {supported}
OPTIONAL, logicalChannelSR-DelayTimerSidelink-r16 ENUMERATED
{supported} OPTIONAL, ... } -- TAG-SIDELINKPARAMETERS-STOP --
ASN1STOP
[0366] UE-NR-Capability
[0367] The IE UE-NR-Capability is used to convey the NR UE Radio
Access Capability Parameters, see TS 38.306 [26].
TABLE-US-00002 UE-NR-Capability information element -- ASN1START --
TAG-UE-NR-CAPABILITY-START ... UE-NR-Capability-v16xy ::= SEQUENCE
{ inDeviceCoexInd-r16 ENUMERATED {supported} OPTIONAL,
dl-DedicatedMessageSegmentation-r16 ENUMERATED {supported}
OPTIONAL, nru-Parameters-r16 NRU-Parameters-r16 OPTIONAL,
sidelinkParameters-r16 SidelinkParameters-r16 OPTIONAL,
bandCombinationListSidelink-r16 BandCombinationListSidelink-r16
OPTIONAL, nonCriticalExtension SEQUENCE { } OPTIONAL } ... --
TAG-UE-NR-CAPABILITY-STOP -- ASN1STOP
[0368] 3GPP TR 23.752 introduces the issue on support of UE-to-UE
Relay and related solutions for a new release (i.e. Release 17) as
follows:
5.4 Key Issue #4: Support of UE-to-UE Relay
5.4.1 General Description
[0369] This key issue intends to support for UE-to-UE Relay,
including support for in coverage and out of coverage
operation.
[0370] At least the following aspects need to be considered in
potential solutions: [0371] How to (re)-select a UE-to-UE Relay UE
in proximity? [0372] Whether and how for the network can control
the UE-to-UE Relay operation, at least including how to: [0373]
Authorize the UE-to-UE Relay, e.g. authorize a UE as UE-to-UE
Relay? [0374] Provide the visibility of source/target UE and the
UE-to-UE Relay to the network for the purpose of, e.g. charging?
[0375] How to establish the connection between the source UE and
the target UEs via UE-to-UE Relay? [0376] How to provide end-to-end
QoS framework to satisfy the QoS requirements (such as data rate,
reliability, latency)? [0377] How to enhance the system
architecture to provide the security protection for relayed
connection? [0378] How to provide a mechanism for path changing in
case of e.g. UE-to-UE Relay changes? [0379] NOTE 1: For the
involvement of NG-RAN, coordination with RAN WGs is needed. [0380]
NOTE 2: For security aspects, coordination with SA3 is needed. [ .
. . ] 6.8 Solution #8: UE-to-UE Relay Selection without Relay
Discovery
6.8.1 Description
[0381] This proposal aims to ensure the relay discovery between the
source and the target UE shall not be dependent on how the relay
forward traffic between the source and the target UE, e.g. L2 or L3
relaying. This solution relies on the concept that the UE-to-UE
discovery and selection can be integrated into the unicast link
establishment procedure as described in clause 6.3.3 of TS 23.287
[5].
[0382] A new field is proposed to be added in the direct
communication request to indicate whether relays can be used in the
communication. The field can be called relay_indication. When a UE
wants to broadcast a direct communication request, it indicates in
the message whether a UE-to-UE relay could be used. For Release 17,
it is assumed that the value of the indication is restricted to
single hop.
[0383] When a UE-to-UE relay receives a direct communication
request with the relay_indication set, then it shall decide whether
to forward the request (i.e. broadcast this request in its
proximity), according to e.g. the QoS requirements in the request,
the current traffic load of the relay, the radio conditions between
the source UE and the relay UE, or some other policies (e.g. it
only serves some specific UEs or services).
[0384] It may be the situation where multiple UE-to-UE relays can
be used to reach the target UE or the target UE may also directly
receive the direct communication request from the source UE. The
target UE may choose which one to reply according to e.g. signal
strength, local policy (e.g. traffic load of the UE-to-UE relays)
or operator policies (e.g. always prefer direct communication or
only use some specific UE-to-UE relays).
[0385] The source UE may receive the direct communication accept
message from multiple UE-to-UE relays and also from the target UE
directly, the source UE chooses the communication path according to
e.g. signal strength, local policy (e.g. traffic load of the
UE-to-UE relays) or operator policies (e.g. always prefer direct
communication or only use some specific UE-to-UE relays).
[0386] 6.8.2 Procedures
[0387] [FIG. 6.8.2-1 of 3GPP TR 23.752 V0.3.0, Entitled "5G ProSe
UE-to-UE Relay Selection", is Reproduced as FIG. 14]
[0388] FIG. 6.8.2-1 illustrates the procedure of the proposed
method. [0389] 0. UEs are authorized to use the service provided by
the UE-to-UE relays. UE-to-UE relays are authorized to provide
service of relaying traffic among UEs. The authorization and the
parameter provisioning can use solutions for KI #8. [0390] 1. UE-1
wants to establish unicast communication with UE-2 and the
communication can be either through direct link with UE-2 or via a
UE-to-UE relay. Then UE-1 broadcasts directly communication request
with relay_indication=1. The request will be received by relay-1,
relay-2. The request may also be received by UE-2 if it is in the
proximity of UE-1. [0391] 2. Relay-1 and relay-2 decide to forward
the request. They broadcast the message in their proximity with
relay_indication=0. If a relay receives this message, it will just
drop it. [0392] 3. UE-2 receives the requests from relay-1 and
relay-2. [0393] 4. UE-2 chooses relay-1 and replies with request
accept. If UE-2 directly receives the direct communication request
from UE-1, it may choose to setup a direct communication link by
sending the request accept directly to UE-1. The response message
includes indication on the type of communication link being
established (e.g. via relay or direct). [0394] 5. UE-1 receives the
request accept from relay-1. UE-1 chooses path according to e.g.
policies (e.g. always choose direct path if it is possible), signal
strength, etc. If UE-1 receives request accept directly from UE-2,
it may choose to setup a direct L2 link as described in clause
6.3.3 of TS 23.287 [5], then step 6 is skipped. [0395] 6. UE-1 and
UE-2 setup communication link through chosen UE-to-UE relay. The
link setup information may vary depending on the type of relay,
e.g. L2 or L3 relaying. [0396] NOTE 1: In order to make a relay or
path selection, the source UE can setup a timer after sending out
the direct communication request for collecting the corresponding
request accept messages before making a decision. Similarly, the
target UE can also setup a timer after receiving the first copy of
the direct communication request for collecting multiple copies of
the request from different paths before making a decision. [0397]
NOTE 2: In the first time when a UE receives a message from a
UE-to-UE relay, the UE needs to verify if the relay is authorized
be a UE-to-UE relay. The verification details and the how to secure
the communication between two UEs through a UE-to-UE relay is to be
defined by SA WG3.
6.8.3 Impacts on Existing Nodes and Functionality
[0398] UE impacts to support new Relay related functions.
6.9 Solution #9: Connection Establishment Via UE-to-UE Layer-2
Relay
6.9.1 Description
[0399] Using the solution described in this clause, a UE-to-UE
Relay enables the discovery of a source UE by a target UE. A
UE-to-UE Relay is authorized to relay messages between two UEs over
the PC5 interface via authorization and provisioning, as defined in
clause 6.Y Solution for Key Issue #4: UE-to-UE Relay Authorization
and Provisioning.
[0400] The source UE announces its supported applications or
discovers a target UE using a known discovery mechanism, e.g. using
user-oriented or service-oriented methods as defined in TS 23.287
[5].
[0401] The UE-to-UE Relay listens for ProSe applications
advertisements (e.g. Direct Discovery or Direct Communication
Request messages) from surrounding UEs and if a broadcasted
application matches one of the applications from its provisioned
relay policy/parameters, the UE-to-UE Relay advertises it as a
relayed application by adding a relay indication to the
message.
[0402] A target UE discovers a source UE via a UE-to-UE Relay. The
target UE receives a broadcast Direct Communication Request message
with a relay indication.
[0403] A secured "extended" PC5 link is set up between the source
UE and the target UE via the UE-to-UE Relay. The source/target UEs
do not know their respective peer UE's L2 IDs. Source/Target UEs
send messages to the UE-to-UE Relay and receive messages through
the UE-to-UE Relay. However, the security association and the PC5
unicast link are established directly between the source UE and
target UE. The UE-to-UE Relay forwards the messages in opaque mode,
without the ability to read, modify their content or replay them.
The source/target UEs detect that the communication is going
through a UE-to-UE Relay upon detecting a relay indication included
in the received messages.
[0404] The UE-to-UE Relay assigns itself two Relay-L2 IDs when a
unicast link is established between two peer UEs via the UE-to-UE
Relay. The first Relay-L2 ID is used when forwarding a message to
the target UE. The second Relay-L2 ID is used when forwarding a
message to the source UE. The UE-to-UE Relay maintains a mapping
table containing the mapping of peer UEs L2 IDs and the
corresponding Relay-L2 IDs that have been self-assigned. When
receiving a message, the UE-to-UE Relay uses its mappings table to
find the source and destination IDs to be used to forward the
message to the target UE. The UE-to-UE Relay uses the Relay-L2 ID
specified in the destination field to find the related UE and uses
the UE's L2 ID specified in the source field to find the related
Relay-L2 ID. It then updates the source and destination fields of
the received message with its corresponding UE's L2 ID and Relay-L2
ID before forwarding the message. [0405] NOTE: Additional
security-related parameters and procedures may be needed for the
protection of relay related messages. Their definitions need to be
coordinated with SA WG3.
6.9.2 Procedures
[0406] The two methods defined in TS 23.287 [5], i.e.
service-oriented and user-oriented are supported using the
procedure described in this clause.
[0407] FIG. 6.9.2-1 shows the peer discovery and unicast link
establishment over PC5 reference point via a UE-to-UE Relay.
[0408] [FIG. 6.9.2-1 of 3GPP TR 23.752 V0.3.0, Entitled "Connection
Establishment Procedure Via a UE-to-UE Relay", is Reproduced as
FIG. 15] [0409] 0. UE-to-UE Relay registers with the network and
specifies its UE-to-UE Relay capabilities. UE-to-UE Relay is
provisioned from the network with relay policy parameters and with
a unique Relay identifier (RID). [0410] 1. The target UEs (i.e.
UE2, UE3 and UE4) determine the destination Layer-2 ID for
signalling reception for PC5 unicast link establishment as
specified in TS 23.287 [5] clause 5.6.1.4. The destination Layer-2
ID is configured with the target UEs as specified in TS 23.287 [5]
clause 5.1.2.1. [0411] 2. On the source UE (i.e. UE1), the
application layer provides information to the ProSe layer for PC5
unicast communication (e.g. broadcast Layer-2 ID, ProSe Application
ID, UE's Application Layer ID, target UE's Application Layer ID,
relay applicable indication), as specified in TS 23.287 [5] clause
6.3.3.1. [0412] 3. ProSe layer triggers the peer UE discovery
mechanism by sending a broadcast Direct Communication Request
message. The message is sent using the source Layer-2 ID and
broadcast Layer-2 ID as destination, and includes other parameters
related to the application offered, as specified in TS 23.287 [5]
clause 6.3.3.1. [0413] 4. The UE-to-UE Relay receives the broadcast
Direct Communication Request message and verifies if it's
configured to relay this application, i.e. it compares the announce
ProSe Application ID with its provisioned relay policy/parameters
and, if it matches, the UE-to-UE Relay assigns itself a
Relay-Layer-2 ID (e.g. R-L2 ID-a) for UE1 (i.e. related to UE1's L2
ID).
[0414] These 2 IDs (UE1's Layer-2 ID and Relay-Layer-2 ID-a) are
saved in a local mapping table. The UE-to-UE Relay overrides the
source field of the message with its R-L2 ID-a and adds its unique
relay identifier (RID) as a relay indication. This relay indication
is added by the UE-to-UE Relay only on broadcast messages since
these messages are sent in clear text (i.e. without any encryption
or integrity protection) thus may be modified. The UE-to-UE Relay
proceeds in forwarding the broadcast Direct Communication Request
message received from the source UE. [0415] 5. Target UE3 is
interested in the announced application thus, it triggers the
authentication and security establishment with UE1, via the
UE-to-UE Relay. UE3 keeps track of the Relay's identifiers, i.e.
R-L2 ID-a and RID. UE3 sends the RID in a security protected
message during the authentication and security establishment to
inform UE1 that the communication is traversing the UE-to-UE Relay
identified by RID.
[0416] UE-to-UE Relay receives the message from UE3 and uses the
R-L2 ID-a specified in the destination field to find the related UE
(i.e. UE1 in this case) in its mapping table.
[0417] UE-to-UE Relay assigns itself a new Layer-2 ID (e.g. R-L2
ID-b) for UE3 and stores the mapping between UE3's L2 ID and R-L2
ID-b.
[0418] UE-to-UE Relay sets the source field of the message to R-L2
ID-b and sets the destination field to UE1's Layer-2 ID (i.e. L2
ID1) retrieved from the mapping entry. UE-to-UE Relay sends the
message to UE1.
[0419] UE1 receives the authentication message and keeps track of
R-L2 ID-b and RID. R-L2 ID-b is used as the destination on
subsequent messages destined to UE3 and sent via the UE-to-UE
Relay.
[0420] Authentication and security establishment messages are
exchanged between UE1 and UE3 via the UE-to-UE Relay. UE-to-UE
Relay changes the source/destination Layer-2 IDs based on the
information saved in its local mapping table. [0421] Editor's note:
The Details of the authentication and security procedure will be
investigated by SA WG3 group. [0422] 6. Once the security is
established, UE3 completes the unicast link establishment by
sending a Direct Communication Accept message. [0423] 7. UE-to-UE
Relay receives the message and sets the source field of the message
to the R-L2 ID-b as found in the mapping entry and sets the
destination field to the UE1's L2 ID also from the mapping entry.
UE-to-UE Relay sends the modified message to UE1. [0424] 8. An
"extended" unicast link is established between UE1 and UE3, via the
UE-to-UE Relay. The extended link is secured end to end, i.e. a
security association has been created between UE1 and UE3.
Confidentiality and/or integrity/replay protected messages (i.e.
data or PC5-S) may be exchanged between UE1 and UE3. The UE-to-UE
Relay is not involved in the security association thus it cannot
read nor modify the secured portion of the message (which excludes
the source and destination fields). [0425] Editor's note: The
details of protocol stack and PC5 link establishment is FFS and
need to be co-ordinated and confirmed by RAN WG2 group.
6.9.3 Impacts on Services, Entities and Interfaces
[0426] The solution has impacts in the following entities:
UE:
[0427] Needs to support procedures for ProSe 5G UE-to-UE Relay and
communications via a ProSe 5G UE-to-UE Relay. 6.10 Solution #10:
ProSe 5G Layer-3 UE-to-UE Relay based on IP routing
6.10.1 Description
[0428] In this solution, the ProSe 5G UE-to-UE Relay operations is
supported with the following principles: [0429] Authorization and
configuration: [0430] Only the UE authorized by the service
authorization configuration can act as a ProSe 5G UE-to-UE Relay.
These UEs will be configured according to the service authorization
and provisioning mechanism defined in TS 23.287 [5] to operate in
the UE-to-UE Relay mode. [0431] ProSe 5G UE-to-UE Relay discovery:
[0432] The ProSe 5G UE-to-UE Relay sends out a Relay Discovery
message periodically, announcing its availability for serving other
UEs in the area. [0433] The ProSe 5G UE-to-UE Relay also supports
the query and response mode for discovery. The ProSe 5G UE-to-UE
Relay listens on a configured Layer-2 ID for the query, and would
respond with its address and corresponding information to enable to
other UE to establish a unicast connection with it. This process is
similar to the unicast L2 link establishment procedure as defined
in TS 23.287 [5] clause 6.3.3.1. [0434] NOTE 1: The Layer-2 ID used
for the discovery can be specific for UE-to-UE Relay discovery, or
shared with other discoveries, e.g. UE-to-Network Relay discovery.
[0435] ProSe 5G UE-to-UE Relay operation: [0436] Any UE that wants
to make use of the ProSe 5G UE-to-UE Relay needs to establish a
unicast L2 link with the UE-to-UE Relay, with IP configuration. The
ProSe 5G UE-to-UE Relay allocates IP address/prefix to the other
UEs. [0437] As part of the unicast L2 link establishment procedure,
the ProSe 5G UE-to-UE Relay stores an association of the User Info
of the peer UE of the unicast link and the IP address/prefix
allocated to the UE into its DNS entries. The ProSe 5G UE-to-UE
Relay acts as a DNS server to other UEs. [0438] When a (source) UE
needs to communicate with another (target) UE or needs to discover
a ProSe service via the ProSe 5G UE-to-UE Relay, it sends a DNS
query for the target UE (based on Target User Info) or for the
ProSe Service to the ProSe 5G UE-to-UE Relay over the unicast link,
which will return the IP address/prefix of the target UE or the
ProSe Service. [0439] The source UE sends the IP data or non-IP
data encapsulated in IP to the target UE via the unicast L2 link to
UE-to-UE Relay that returned the IP address/prefix of the target
UE. The ProSe 5G UE-to-UE Relay acts as an IP router, and forwards
the packets to the corresponding unicast L2 link towards the target
UE. Each of the unicast L2 link is treated as an IP interface.
[0440] If there are multiple ProSe 5G UE-to-UE Relays in the
proximity, UE can choose either one or more ProSe 5G UE-to-UE
Relays to establish the unicast L2 link based on UE implementation.
For example, the UE sends a DNS query on each of the unicast L2
link to the ProSe 5G UE-to-UE Relays. Then, the source UE may
choose to use the first ProSe 5G UE-to-UE Relay that returns a
positive DNS query for the target UE. [0441] NOTE 2: The selection
of the UE-to-UE Relay may be based on local configured rules on the
UE, or based on other discovery solutions, e.g. "Stateful UE-to-UE
Relay" described in clause 6.11. [0442] QoS handling: [0443] When
the source UE establishes the unicast L2 link with the ProSe 5G
UE-to-UE Relay, it can establish corresponding PC5 QoS Flows
according to procedure defined in clause 6.3.3.1 of TS 23.287 [5].
It can also modify the PC5 QoS Flows at any time using procedure
defined in clause 6.3.3.4 of TS 23.287 [5]. [0444] Correspondingly,
the ProSe 5G UE-to-UE Relay can also establish and modify the PC5
QoS Flows using the above-mentioned procedures over the unicast L2
Link with the target UE for the forwarding of source UE's traffic.
[0445] Security handling: [0446] source UE and target UE can
establish bearer level security with the UE-to-UE Relay for the
unicast L2 Link, using procedures defined in TS 23.287 [5]. [0447]
If end-to-end security protection is required between source UE and
target UE, IPSec can be used. [0448] NOTE 3: The security
protection of the traffic of source UE and target UE will be
specified by SA WG3. [0449] Charging Support: [0450] ProSe 5G
UE-to-UE Relay can follow the charging solution defined in TS
32.277 [13] to report the source and target UEs and corresponding
traffic to the charging function.
6.10.2 Procedures
[0451] [FIG. 6.10.2-1 of 3GPP TR 23.752 V0.3.0, Entitled "5G ProSe
UE-to-UE Relay Operation", is Reproduced as FIG. 16]
[0452] FIG. 6.10.2-1 provides an example operation for the 5G ProSe
UE-to-UE Relay operation based on standard IP operation.
6.10.3 Impacts on Services, Entities and Interfaces
[0453] There is no impact to NG-RAN, as the solution is using the
existing features supported in Rel-16 NR V2X design.
[0454] UEs operates with existing IP operation, and the ProSe 5G
UE-to-UE Relay supports the IP router function (for address
allocation and traffic forwarding) and the functionality of a DNS
server.
[ . . . ]
[0455] In a legacy NR system (as discussed in 3GPP TS 38.331), a UE
shall report its UE capability information to gNB and the UE
capability information includes sidelink UE capability information
(i.e. SidelinkParameters) of the UE. Two UEs engaged in unicast
communication shall exchange sidelink UE capability information in
the sidelink UE capability transfer procedure. In addition, the UE
shall include the UECapabilityInformationSidelink message received
from the peer UE in a SidelinkUEinformationNR message reported to
gNB (as discussed in 3GPP R2-2005973).
[0456] Besides, a UE needs to transmit a Sidelink UE Information
message (i.e. a SidelinkUEinformationNR message) to gNB to request
sidelink resource (or sidelink configuration) for sidelink
communication with a destination (as discussed in 3GPP TS 38.331),
wherein the destination included in this message may be a peer UE
(for a direct sidelink communication) or a UE-to-UE Relay (for a
sidelink communication via the Relay).
[0457] Key issue #4 in 3GPP TR 23.752 describes support of UE-to-UE
Relay in the next release (i.e. Release 17), which means a relay
may be used to support data communication between two UEs in case
these two UEs cannot communicate with each other directly. It is
supposed that a UE-to-UE Relay needs to establish one PC5 unicast
link with each of a Source UE and a Target UE such that the
integrated PC5 unicast link between the Source UE and the Target UE
can support the concerned ProSe service as illustrated in FIG. 17,
which shows an example of Integrated PC5 unicast link via a User
Equipment-to-User Equipment (UE-to-UE) Relay according to one
embodiment.
[0458] Given two PC5 unicast links are established between a
UE-to-UE Relay and each of the Source UE and the Target UE, it is
possible that the data rates on these two PC5 unicast links may be
different because different sets of UE capability information are
taken into consideration by gNB to allocate sidelink DRB
configurations for both PC5 unicast links. In this situation, data
from one side may accumulate in the buffer of the UE-to-UE Relay,
which may cause problems in the UE-to-UE Relay e.g. data loss due
to shortage of buffer.
[0459] To ensure similar data rates on both PC5 unicast links, one
potential way is for the UE-to-UE Relay to transfer the sidelink UE
capability information of one UE (e.g. the Source UE) to the other
UE (e.g. the Target UE), in addition to the sidelink UE capability
information of the UE-to-UE Relay, so that the UE may transmit the
peer UE's sidelink UE capability information to gNB for requesting
sidelink resource (or sidelink configuration). For example, the UE
may include the peer UE's sidelink UE capability information and
the UE-to-UE Relay's sidelink UE capability information in a
Sidelink UE Information message sent to gNB. It is also feasible
for the UE to include a combined sidelink UE capability
information, which is derived from the peer UE's sidelink UE
capability information and the UE-to-UE Relay's sidelink UE
capability information e.g. a value of a lower capability between
two capability parameters in both the peer UE's sidelink UE
capability information and the UE-to-UE Relay's sidelink UE
capability information is selected to form a corresponding
capability parameter in the combined sidelink UE capability
information. FIG. 18 shows an example of an integrated sidelink UE
capability transfer procedure performed by three parties including
the UE (UE1), the UE-to-UE Relay, and the peer UE (UE2), according
to one embodiment.
[0460] It is also possible for the UE to transmit the peer UE's
sidelink UE capability information and the UE-to-UE Relay's
sidelink UE capability information in two separate RRC messages to
gNB.
[0461] Alternatively, the UE-to-UE Relay may transmit, to one UE, a
combined sidelink UE capability information, which is derived from
the UE-to-UE Relay's sidelink UE capability information and the
peer UE's sidelink UE capability information as described above. By
this way, the UE may just include the combined sidelink UE
capability information in the Sidelink UE Information message sent
to gNB.
[0462] To support the above general concepts, the UE-to-UE Relay
may transmit both UEs' sidelink UE capability information to gNB
when requesting sidelink resource (or sidelink configuration) for
the sidelink communication. It is also feasible for the UE-to-UE
Relay to transmit a combined sidelink UE capability information,
which is derived from both UEs' sidelink UE capability information
as described above.
[0463] Basically, each of the Source UE, the Target UE, and the
UE-to-UE Relay may transmit its own sidelink UE capability
information to its serving gNB in a UECapabilityInformation message
after connecting with the gNB.
[0464] It is possible that a new term may be used for the sidelink
UE capability information of a UE-to-UE Relay if there is a need to
distinguish a UE-to-UE Relay from a UE. In this situation, another
term may also be used for the combined sidelink UE capability
information.
[0465] FIG. 19 is a flow chart 1900 according to one exemplary
embodiment from the perspective of a second UE to report sidelink
capability information. In step 1905, the second UE receives, from
a UE-to-UE Relay, a first sidelink UE capability information of a
first UE and a second sidelink UE capability information of the
UE-to-UE Relay or receives, from the UE-to-UE Relay, a combined
sidelink UE capability information, wherein the combined sidelink
UE capability information is derived from the first sidelink UE
capability information and the second sidelink UE capability
information. In step 1910, the second UE transmits the first
sidelink UE capability information and the second sidelink UE
capability information to a network node or transmits the combined
sidelink UE capability information to the network node.
[0466] In one embodiment, the first UE could communicate with the
second UE via the UE-to-UE Relay.
[0467] In one embodiment, the first sidelink UE capability
information and the second sidelink UE capability information could
be received via one first PC5 Radio Resource Control (RRC) message,
two first PC5 RRC messages, or a first PC5 RRC message and a second
PC5 RRC message. The first PC5 RRC message may be a
UECapabilityEnquirySidelink message or a
UECapabilityInformationSidelink message. The second PC5 RRC message
may be a UECapabilityEnquirySidelink message or a
UECapabilityInformationSidelink message.
[0468] In one embodiment, the combined sidelink UE capability
information could be transmitted to the network node via a Sidelink
UE Information message. The first sidelink UE capability
information and the second sidelink UE capability information could
be transmitted to the network node via a Sidelink UE Information
message. The Sidelink UE Information message may include a
destination identity of the UE-to-UE Relay, a cast type of the
sidelink communication, and/or Quality of Service (QoS) information
of a PC5 QoS flow. The cast type may be set to "unicast". The QoS
information may include a QoS flow identity and a QoS profile.
[0469] In one embodiment, the second UE could transmit a third
sidelink UE capability information of the second UE to the network
node. The third sidelink UE capability information could be
transmitted in a UE Capability Information message.
[0470] In one embodiment, the second UE could receive a Radio
Resource Control (RRC) Reconfiguration message from the network
node to allocate a sidelink configuration for the sidelink
communication. The sidelink configuration may include a
configuration of a sidelink Data Radio Bearer (DRB) mapped to a PC5
QoS flow.
[0471] Referring back to FIGS. 3 and 4, in one exemplary embodiment
of a second UE to report sidelink UE capability information, the
second UE 300 includes a program code 312 stored in the memory 310.
The CPU 308 could execute program code 312 to enable the second UE
(i) to receive, from a UE-to-UE Relay, a first sidelink UE
capability information of a first UE and a second sidelink UE
capability information of the UE-to-UE Relay or receives, from the
UE-to-UE Relay, a combined sidelink UE capability information,
wherein the combined sidelink UE capability information is derived
from the first sidelink UE capability information and the second
sidelink UE capability information, and (ii) to transmit the first
sidelink UE capability information and the second sidelink UE
capability information to a network node or transmits the combined
sidelink UE capability information to the network node.
Furthermore, the CPU 308 can execute the program code 312 to
perform all of the above-described actions and steps or others
described herein.
[0472] Various aspects of the disclosure have been described above.
It should be apparent that the teachings herein could be embodied
in a wide variety of forms and that any specific structure,
function, or both being disclosed herein is merely representative.
Based on the teachings herein one skilled in the art should
appreciate that an aspect disclosed herein could be implemented
independently of any other aspects and that two or more of these
aspects could be combined in various ways. For example, an
apparatus could be implemented or a method could be practiced using
any number of the aspects set forth herein. In addition, such an
apparatus could be implemented or such a method could be practiced
using other structure, functionality, or structure and
functionality in addition to or other than one or more of the
aspects set forth herein. As an example of some of the above
concepts, in some aspects concurrent channels could be established
based on pulse repetition frequencies. In some aspects concurrent
channels could be established based on pulse position or offsets.
In some aspects concurrent channels could be established based on
time hopping sequences. In some aspects concurrent channels could
be established based on pulse repetition frequencies, pulse
positions or offsets, and time hopping sequences.
[0473] Those of skill in the art would understand that information
and signals may be represented using any of a variety of different
technologies and techniques. For example, data, instructions,
commands, information, signals, bits, symbols, and chips that may
be referenced throughout the above description may be represented
by voltages, currents, electromagnetic waves, magnetic fields or
particles, optical fields or particles, or any combination
thereof.
[0474] Those of skill would further appreciate that the various
illustrative logical blocks, modules, processors, means, circuits,
and algorithm steps described in connection with the aspects
disclosed herein may be implemented as electronic hardware (e.g., a
digital implementation, an analog implementation, or a combination
of the two, which may be designed using source coding or some other
technique), various forms of program or design code incorporating
instructions (which may be referred to herein, for convenience, as
"software" or a "software module"), or combinations of both. To
clearly illustrate this interchangeability of hardware and
software, various illustrative components, blocks, modules,
circuits, and steps have been described above generally in terms of
their functionality. Whether such functionality is implemented as
hardware or software depends upon the particular application and
design constraints imposed on the overall system. Skilled artisans
may implement the described functionality in varying ways for each
particular application, but such implementation decisions should
not be interpreted as causing a departure from the scope of the
present disclosure.
[0475] In addition, the various illustrative logical blocks,
modules, and circuits described in connection with the aspects
disclosed herein may be implemented within or performed by an
integrated circuit ("IC"), an access terminal, or an access point.
The IC may comprise a general purpose processor, a digital signal
processor (DSP), an application specific integrated circuit (ASIC),
a field programmable gate array (FPGA) or other programmable logic
device, discrete gate or transistor logic, discrete hardware
components, electrical components, optical components, mechanical
components, or any combination thereof designed to perform the
functions described herein, and may execute codes or instructions
that reside within the IC, outside of the IC, or both. A general
purpose processor may be a microprocessor, but in the alternative,
the processor may be any conventional processor, controller,
microcontroller, or state machine. A processor may also be
implemented as a combination of computing devices, e.g., a
combination of a DSP and a microprocessor, a plurality of
microprocessors, one or more microprocessors in conjunction with a
DSP core, or any other such configuration.
[0476] It is understood that any specific order or hierarchy of
steps in any disclosed process is an example of a sample approach.
Based upon design preferences, it is understood that the specific
order or hierarchy of steps in the processes may be rearranged
while remaining within the scope of the present disclosure. The
accompanying method claims present elements of the various steps in
a sample order, and are not meant to be limited to the specific
order or hierarchy presented.
[0477] The steps of a method or algorithm described in connection
with the aspects disclosed herein may be embodied directly in
hardware, in a software module executed by a processor, or in a
combination of the two. A software module (e.g., including
executable instructions and related data) and other data may reside
in a data memory such as RAM memory, flash memory, ROM memory,
EPROM memory, EEPROM memory, registers, a hard disk, a removable
disk, a CD-ROM, or any other form of computer-readable storage
medium known in the art. A sample storage medium may be coupled to
a machine such as, for example, a computer/processor (which may be
referred to herein, for convenience, as a "processor") such the
processor can read information (e.g., code) from and write
information to the storage medium. A sample storage medium may be
integral to the processor. The processor and the storage medium may
reside in an ASIC. The ASIC may reside in user equipment. In the
alternative, the processor and the storage medium may reside as
discrete components in user equipment. Moreover, in some aspects
any suitable computer-program product may comprise a
computer-readable medium comprising codes relating to one or more
of the aspects of the disclosure. In some aspects a computer
program product may comprise packaging materials.
[0478] While the invention has been described in connection with
various aspects, it will be understood that the invention is
capable of further modifications. This application is intended to
cover any variations, uses or adaptation of the invention
following, in general, the principles of the invention, and
including such departures from the present disclosure as come
within the known and customary practice within the art to which the
invention pertains.
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